diff --git a/core/object/object.cpp b/core/object/object.cpp
index a5f6f48b7f8..fd32c0a90ab 100644
--- a/core/object/object.cpp
+++ b/core/object/object.cpp
@@ -1650,6 +1650,19 @@ bool Object::_uses_signal_mutex() const {
 	return true;
 }
 
+String Object::_get_locale() const {
+	TranslationServer *ts = TranslationServer::get_singleton();
+	const StringName domain_name = get_translation_domain();
+	if (ts->has_domain(domain_name)) {
+		const Ref<TranslationDomain> domain = ts->get_or_add_domain(domain_name);
+		const String &overridden = domain->get_locale_override();
+		if (!overridden.is_empty()) {
+			return overridden;
+		}
+	}
+	return ts->get_locale();
+}
+
 void Object::_set_bind(const StringName &p_set, const Variant &p_value) {
 	set(p_set, p_value);
 }
diff --git a/core/object/object.h b/core/object/object.h
index c0e33457973..82cec498e1f 100644
--- a/core/object/object.h
+++ b/core/object/object.h
@@ -793,6 +793,9 @@ protected:
 
 	virtual bool _uses_signal_mutex() const;
 
+	// Internal helper to get the current locale, taking into account the translation domain.
+	String _get_locale() const;
+
 #ifdef TOOLS_ENABLED
 	struct VirtualMethodTracker {
 		void **method;
diff --git a/editor/editor_node.cpp b/editor/editor_node.cpp
index 2c5b21e8bba..c2dc503622d 100644
--- a/editor/editor_node.cpp
+++ b/editor/editor_node.cpp
@@ -453,6 +453,10 @@ void EditorNode::_update_from_settings() {
 	String current_fallback_locale = GLOBAL_GET("internationalization/locale/fallback");
 	if (current_fallback_locale != TranslationServer::get_singleton()->get_fallback_locale()) {
 		TranslationServer::get_singleton()->set_fallback_locale(current_fallback_locale);
+		Ref<TranslationDomain> domain = TranslationServer::get_singleton()->get_main_domain();
+		if (!domain->is_enabled()) {
+			domain->set_locale_override(current_fallback_locale);
+		}
 		scene_root->propagate_notification(Control::NOTIFICATION_LAYOUT_DIRECTION_CHANGED);
 	}
 
@@ -4175,8 +4179,15 @@ void EditorNode::set_preview_locale(const String &p_locale) {
 	// Texts set in the editor could be identifiers that should never be translated.
 	// So we need to disable translation entirely.
 	Ref<TranslationDomain> main_domain = TranslationServer::get_singleton()->get_main_domain();
-	main_domain->set_enabled(!p_locale.is_empty());
-	main_domain->set_locale_override(p_locale);
+	if (p_locale.is_empty()) {
+		// Disable preview. Use the fallback locale.
+		main_domain->set_enabled(false);
+		main_domain->set_locale_override(TranslationServer::get_singleton()->get_fallback_locale());
+	} else {
+		// Preview a specific locale.
+		main_domain->set_enabled(true);
+		main_domain->set_locale_override(p_locale);
+	}
 
 	_translation_resources_changed();
 }
@@ -7574,7 +7585,10 @@ EditorNode::EditorNode() {
 	ProjectSettings::get_singleton()->connect("settings_changed", callable_mp(this, &EditorNode::_update_from_settings));
 	GDExtensionManager::get_singleton()->connect("extensions_reloaded", callable_mp(this, &EditorNode::_gdextensions_reloaded));
 
-	TranslationServer::get_singleton()->get_main_domain()->set_enabled(false);
+	Ref<TranslationDomain> domain = TranslationServer::get_singleton()->get_main_domain();
+	domain->set_enabled(false);
+	domain->set_locale_override(TranslationServer::get_singleton()->get_fallback_locale());
+
 	// Load settings.
 	if (!EditorSettings::get_singleton()) {
 		EditorSettings::create();
diff --git a/scene/3d/label_3d.cpp b/scene/3d/label_3d.cpp
index 2b511bac9af..60ceba70a74 100644
--- a/scene/3d/label_3d.cpp
+++ b/scene/3d/label_3d.cpp
@@ -214,11 +214,8 @@ void Label3D::_notification(int p_what) {
 			window->disconnect("size_changed", callable_mp(this, &Label3D::_font_changed));
 		} break;
 		case NOTIFICATION_TRANSLATION_CHANGED: {
-			String new_text = atr(text);
-			if (new_text == xl_text) {
-				return; // Nothing new.
-			}
-			xl_text = new_text;
+			// Language update might change the appearance of some characters.
+			xl_text = atr(text);
 			dirty_text = true;
 			_queue_update();
 		} break;
@@ -482,8 +479,9 @@ void Label3D::_shape() {
 		TS->shaped_text_clear(text_rid);
 		TS->shaped_text_set_direction(text_rid, text_direction);
 
-		String txt = (uppercase) ? TS->string_to_upper(xl_text, language) : xl_text;
-		TS->shaped_text_add_string(text_rid, txt, font->get_rids(), font_size, font->get_opentype_features(), language);
+		const String &lang = language.is_empty() ? _get_locale() : language;
+		String txt = uppercase ? TS->string_to_upper(xl_text, lang) : xl_text;
+		TS->shaped_text_add_string(text_rid, txt, font->get_rids(), font_size, font->get_opentype_features(), lang);
 
 		TypedArray<Vector3i> stt;
 		if (st_parser == TextServer::STRUCTURED_TEXT_CUSTOM) {
diff --git a/scene/gui/button.cpp b/scene/gui/button.cpp
index 2fac6ee0537..6cce9115371 100644
--- a/scene/gui/button.cpp
+++ b/scene/gui/button.cpp
@@ -600,7 +600,8 @@ void Button::_shape(Ref<TextParagraph> p_paragraph, String p_text) const {
 	} else {
 		p_paragraph->set_direction((TextServer::Direction)text_direction);
 	}
-	p_paragraph->add_string(p_text, font, font_size, language);
+	const String &lang = language.is_empty() ? _get_locale() : language;
+	p_paragraph->add_string(p_text, font, font_size, lang);
 	p_paragraph->set_text_overrun_behavior(overrun_behavior);
 }
 
diff --git a/scene/gui/code_edit.cpp b/scene/gui/code_edit.cpp
index 56d15231b4d..5c9a69b1e92 100644
--- a/scene/gui/code_edit.cpp
+++ b/scene/gui/code_edit.cpp
@@ -188,13 +188,14 @@ void CodeEdit::_notification(int p_what) {
 					code_completion_line_ofs = CLAMP((code_completion_force_item_center < 0 ? code_completion_current_selected : code_completion_force_item_center) - lines / 2, 0, code_completion_options_count - lines);
 					RenderingServer::get_singleton()->canvas_item_add_rect(ci, Rect2(Point2(code_completion_rect.position.x, code_completion_rect.position.y + (code_completion_current_selected - code_completion_line_ofs) * row_height), Size2(code_completion_rect.size.width, row_height)), theme_cache.code_completion_selected_color);
 
+					const String &lang = _get_locale();
 					for (int i = 0; i < lines; i++) {
 						int l = code_completion_line_ofs + i;
 						ERR_CONTINUE(l < 0 || l >= code_completion_options_count);
 
 						Ref<TextLine> tl;
 						tl.instantiate();
-						tl->add_string(code_completion_options[l].display, theme_cache.font, theme_cache.font_size);
+						tl->add_string(code_completion_options[l].display, theme_cache.font, theme_cache.font_size, lang);
 
 						int yofs = (row_height - tl->get_size().y) / 2;
 						Point2 title_pos(code_completion_rect.position.x, code_completion_rect.position.y + i * row_height + yofs);
@@ -1519,14 +1520,15 @@ void CodeEdit::_line_number_draw_callback(int p_line, int p_gutter, const Rect2
 	if (E) {
 		text_rid = E->value;
 	} else {
+		const String &lang = _get_locale();
 		String fc = String::num_int64(p_line + 1).lpad(line_number_digits, line_number_padding);
 		if (is_localizing_numeral_system()) {
-			fc = TS->format_number(fc);
+			fc = TS->format_number(fc, lang);
 		}
 
 		text_rid = TS->create_shaped_text();
 		if (theme_cache.font.is_valid()) {
-			TS->shaped_text_add_string(text_rid, fc, theme_cache.font->get_rids(), theme_cache.font_size, theme_cache.font->get_opentype_features());
+			TS->shaped_text_add_string(text_rid, fc, theme_cache.font->get_rids(), theme_cache.font_size, theme_cache.font->get_opentype_features(), lang);
 		}
 		line_number_text_cache.insert(p_line, text_rid);
 	}
diff --git a/scene/gui/control.cpp b/scene/gui/control.cpp
index 0dc1664d82c..808faf13de6 100644
--- a/scene/gui/control.cpp
+++ b/scene/gui/control.cpp
@@ -35,7 +35,6 @@
 #include "core/input/input_map.h"
 #include "core/os/os.h"
 #include "core/string/string_builder.h"
-#include "core/string/translation_server.h"
 #include "scene/gui/scroll_container.h"
 #include "scene/main/canvas_layer.h"
 #include "scene/main/window.h"
@@ -3516,12 +3515,9 @@ bool Control::is_layout_rtl() const {
 					} else if (proj_root_layout_direction == 2) {
 						data.is_rtl = true;
 					} else if (proj_root_layout_direction == 3) {
-						String locale = OS::get_singleton()->get_locale();
-						data.is_rtl = TS->is_locale_right_to_left(locale);
+						data.is_rtl = TS->is_locale_right_to_left(OS::get_singleton()->get_locale());
 					} else {
-						const Ref<Translation> &t = TranslationServer::get_singleton()->get_translation_object(TranslationServer::get_singleton()->get_locale());
-						String locale = t.is_valid() ? t->get_locale() : TranslationServer::get_singleton()->get_fallback_locale();
-						data.is_rtl = TS->is_locale_right_to_left(locale);
+						data.is_rtl = TS->is_locale_right_to_left(_get_locale());
 					}
 					return data.is_rtl;
 				}
@@ -3532,8 +3528,9 @@ bool Control::is_layout_rtl() const {
 				return data.is_rtl;
 			}
 #endif // TOOLS_ENABLED
+			const StringName domain_name = get_translation_domain();
 			Node *parent_node = get_parent();
-			while (parent_node) {
+			while (parent_node && domain_name == parent_node->get_translation_domain()) {
 				Control *parent_control = Object::cast_to<Control>(parent_node);
 				if (parent_control) {
 					data.is_rtl = parent_control->is_layout_rtl();
@@ -3556,22 +3553,19 @@ bool Control::is_layout_rtl() const {
 				String locale = OS::get_singleton()->get_locale();
 				data.is_rtl = TS->is_locale_right_to_left(locale);
 			} else {
-				String locale = TranslationServer::get_singleton()->get_tool_locale();
-				data.is_rtl = TS->is_locale_right_to_left(locale);
+				data.is_rtl = TS->is_locale_right_to_left(_get_locale());
 			}
 		} else if (data.layout_dir == LAYOUT_DIRECTION_APPLICATION_LOCALE) {
 			if (GLOBAL_GET_CACHED(bool, "internationalization/rendering/force_right_to_left_layout_direction")) {
 				data.is_rtl = true;
 			} else {
-				String locale = TranslationServer::get_singleton()->get_tool_locale();
-				data.is_rtl = TS->is_locale_right_to_left(locale);
+				data.is_rtl = TS->is_locale_right_to_left(_get_locale());
 			}
 		} else if (data.layout_dir == LAYOUT_DIRECTION_SYSTEM_LOCALE) {
 			if (GLOBAL_GET_CACHED(bool, "internationalization/rendering/force_right_to_left_layout_direction")) {
-				const_cast<Control *>(this)->data.is_rtl = true;
+				data.is_rtl = true;
 			} else {
-				String locale = OS::get_singleton()->get_locale();
-				const_cast<Control *>(this)->data.is_rtl = TS->is_locale_right_to_left(locale);
+				data.is_rtl = TS->is_locale_right_to_left(OS::get_singleton()->get_locale());
 			}
 		} else {
 			data.is_rtl = (data.layout_dir == LAYOUT_DIRECTION_RTL);
diff --git a/scene/gui/foldable_container.cpp b/scene/gui/foldable_container.cpp
index c93bab06faf..d64fc16d169 100644
--- a/scene/gui/foldable_container.cpp
+++ b/scene/gui/foldable_container.cpp
@@ -488,7 +488,8 @@ void FoldableContainer::_shape() {
 	}
 	text_buf->set_horizontal_alignment(_get_actual_alignment());
 	text_buf->set_text_overrun_behavior(overrun_behavior);
-	text_buf->add_string(atr(title), font, font_size, language);
+	const String &lang = language.is_empty() ? _get_locale() : language;
+	text_buf->add_string(atr(title), font, font_size, lang);
 }
 
 HorizontalAlignment FoldableContainer::_get_actual_alignment() const {
diff --git a/scene/gui/item_list.cpp b/scene/gui/item_list.cpp
index 333ae07ab64..90b18d6e509 100644
--- a/scene/gui/item_list.cpp
+++ b/scene/gui/item_list.cpp
@@ -43,7 +43,8 @@ void ItemList::_shape_text(int p_idx) {
 	} else {
 		item.text_buf->set_direction((TextServer::Direction)item.text_direction);
 	}
-	item.text_buf->add_string(item.xl_text, theme_cache.font, theme_cache.font_size, item.language);
+	const String &lang = item.language.is_empty() ? _get_locale() : item.language;
+	item.text_buf->add_string(item.xl_text, theme_cache.font, theme_cache.font_size, lang);
 	if (icon_mode == ICON_MODE_TOP && max_text_lines > 0) {
 		item.text_buf->set_break_flags(TextServer::BREAK_MANDATORY | TextServer::BREAK_WORD_BOUND | TextServer::BREAK_GRAPHEME_BOUND | TextServer::BREAK_TRIM_START_EDGE_SPACES | TextServer::BREAK_TRIM_END_EDGE_SPACES);
 	} else {
diff --git a/scene/gui/label.cpp b/scene/gui/label.cpp
index cd97ee265b2..e946364ffa9 100644
--- a/scene/gui/label.cpp
+++ b/scene/gui/label.cpp
@@ -136,6 +136,8 @@ int Label::get_line_height(int p_line) const {
 }
 
 void Label::_shape() const {
+	const String &lang = language.is_empty() ? _get_locale() : language;
+
 	Ref<StyleBox> style = theme_cache.normal_style;
 	int width = (get_size().width - style->get_minimum_size().width);
 
@@ -149,7 +151,7 @@ void Label::_shape() const {
 		}
 		paragraphs.clear();
 
-		String txt = (uppercase) ? TS->string_to_upper(xl_text, language) : xl_text;
+		String txt = (uppercase) ? TS->string_to_upper(xl_text, lang) : xl_text;
 		if (visible_chars >= 0 && visible_chars_behavior == TextServer::VC_CHARS_BEFORE_SHAPING) {
 			txt = txt.substr(0, visible_chars);
 		}
@@ -183,7 +185,7 @@ void Label::_shape() const {
 			ERR_FAIL_COND(font.is_null());
 
 			if (para.dirty) {
-				TS->shaped_text_add_string(para.text_rid, para.text, font->get_rids(), font_size, font->get_opentype_features(), language);
+				TS->shaped_text_add_string(para.text_rid, para.text, font->get_rids(), font_size, font->get_opentype_features(), lang);
 			} else {
 				int spans = TS->shaped_get_span_count(para.text_rid);
 				for (int i = 0; i < spans; i++) {
@@ -703,15 +705,14 @@ void Label::_notification(int p_what) {
 		} break;
 
 		case NOTIFICATION_TRANSLATION_CHANGED: {
-			String new_text = atr(text);
-			if (new_text == xl_text) {
-				return; // Nothing new.
+			const String new_text = atr(text);
+			if (new_text != xl_text) {
+				xl_text = new_text;
+				if (visible_ratio < 1) {
+					visible_chars = get_total_character_count() * visible_ratio;
+				}
 			}
-			xl_text = new_text;
-			if (visible_ratio < 1) {
-				visible_chars = get_total_character_count() * visible_ratio;
-			}
-			text_dirty = true;
+			text_dirty = true; // Language update might change the appearance of some characters.
 
 			queue_accessibility_update();
 			queue_redraw();
diff --git a/scene/gui/line_edit.cpp b/scene/gui/line_edit.cpp
index f188ed693ca..9822086c78b 100644
--- a/scene/gui/line_edit.cpp
+++ b/scene/gui/line_edit.cpp
@@ -1201,11 +1201,8 @@ void LineEdit::_notification(int p_what) {
 			DisplayServer::get_singleton()->accessibility_update_add_action(ae, DisplayServer::AccessibilityAction::ACTION_REPLACE_SELECTED_TEXT, callable_mp(this, &LineEdit::_accessibility_action_replace_selected));
 			DisplayServer::get_singleton()->accessibility_update_add_action(ae, DisplayServer::AccessibilityAction::ACTION_SET_VALUE, callable_mp(this, &LineEdit::_accessibility_action_set_value));
 			DisplayServer::get_singleton()->accessibility_update_add_action(ae, DisplayServer::AccessibilityAction::ACTION_SHOW_CONTEXT_MENU, callable_mp(this, &LineEdit::_accessibility_action_menu));
-			if (!language.is_empty()) {
-				DisplayServer::get_singleton()->accessibility_update_set_language(ae, language);
-			} else {
-				DisplayServer::get_singleton()->accessibility_update_set_language(ae, TranslationServer::get_singleton()->get_tool_locale());
-			}
+			const String &lang = language.is_empty() ? _get_locale() : language;
+			DisplayServer::get_singleton()->accessibility_update_set_language(ae, lang);
 
 			bool rtl = is_layout_rtl();
 			Ref<StyleBox> style = theme_cache.normal;
@@ -2978,7 +2975,8 @@ void LineEdit::_shape() {
 	}
 	TS->shaped_text_set_preserve_control(text_rid, draw_control_chars);
 
-	TS->shaped_text_add_string(text_rid, t, font->get_rids(), font_size, font->get_opentype_features(), language);
+	const String &lang = language.is_empty() ? _get_locale() : language;
+	TS->shaped_text_add_string(text_rid, t, font->get_rids(), font_size, font->get_opentype_features(), lang);
 	TS->shaped_text_set_bidi_override(text_rid, structured_text_parser(st_parser, st_args, t));
 
 	full_width = TS->shaped_text_get_size(text_rid).x;
diff --git a/scene/gui/link_button.cpp b/scene/gui/link_button.cpp
index f9ef144400c..83a3ca9b136 100644
--- a/scene/gui/link_button.cpp
+++ b/scene/gui/link_button.cpp
@@ -43,7 +43,8 @@ void LinkButton::_shape() {
 		text_buf->set_direction((TextServer::Direction)text_direction);
 	}
 	TS->shaped_text_set_bidi_override(text_buf->get_rid(), structured_text_parser(st_parser, st_args, xl_text));
-	text_buf->add_string(xl_text, font, font_size, language);
+	const String &lang = language.is_empty() ? _get_locale() : language;
+	text_buf->add_string(xl_text, font, font_size, lang);
 
 	queue_accessibility_update();
 }
diff --git a/scene/gui/menu_bar.cpp b/scene/gui/menu_bar.cpp
index 9e149aff865..fe8208351e5 100644
--- a/scene/gui/menu_bar.cpp
+++ b/scene/gui/menu_bar.cpp
@@ -517,7 +517,8 @@ void MenuBar::shape(Menu &p_menu) {
 	} else {
 		p_menu.text_buf->set_direction((TextServer::Direction)text_direction);
 	}
-	p_menu.text_buf->add_string(atr(p_menu.name), theme_cache.font, theme_cache.font_size, language);
+	const String &lang = language.is_empty() ? _get_locale() : language;
+	p_menu.text_buf->add_string(atr(p_menu.name), theme_cache.font, theme_cache.font_size, lang);
 }
 
 void MenuBar::_refresh_menu_names() {
diff --git a/scene/gui/popup_menu.cpp b/scene/gui/popup_menu.cpp
index b51233df159..694b3015192 100644
--- a/scene/gui/popup_menu.cpp
+++ b/scene/gui/popup_menu.cpp
@@ -1017,11 +1017,12 @@ void PopupMenu::_shape_item(int p_idx) const {
 		} else {
 			items.write[p_idx].text_buf->set_direction((TextServer::Direction)items[p_idx].text_direction);
 		}
-		items.write[p_idx].text_buf->add_string(items.write[p_idx].xl_text, font, font_size, items[p_idx].language);
+		const String &lang = items[p_idx].language.is_empty() ? _get_locale() : items[p_idx].language;
+		items.write[p_idx].text_buf->add_string(items.write[p_idx].xl_text, font, font_size, lang);
 
 		items.write[p_idx].accel_text_buf->clear();
 		items.write[p_idx].accel_text_buf->set_direction(is_layout_rtl() ? TextServer::DIRECTION_RTL : TextServer::DIRECTION_LTR);
-		items.write[p_idx].accel_text_buf->add_string(_get_accel_text(items.write[p_idx]), font, font_size);
+		items.write[p_idx].accel_text_buf->add_string(_get_accel_text(items.write[p_idx]), font, font_size, lang);
 		items.write[p_idx].dirty = false;
 	}
 }
diff --git a/scene/gui/progress_bar.cpp b/scene/gui/progress_bar.cpp
index f43ddd9cc70..37ae2b1abbc 100644
--- a/scene/gui/progress_bar.cpp
+++ b/scene/gui/progress_bar.cpp
@@ -167,7 +167,8 @@ void ProgressBar::_notification(int p_what) {
 				String txt = itos(int(ratio * 100));
 
 				if (is_localizing_numeral_system()) {
-					txt = TS->format_number(txt) + TS->percent_sign();
+					const String &lang = _get_locale();
+					txt = TS->format_number(txt, lang) + TS->percent_sign(lang);
 				} else {
 					txt += String("%");
 				}
diff --git a/scene/gui/rich_text_label.cpp b/scene/gui/rich_text_label.cpp
index 233c6e54514..f3aa6b7bc24 100644
--- a/scene/gui/rich_text_label.cpp
+++ b/scene/gui/rich_text_label.cpp
@@ -3407,21 +3407,20 @@ TextServer::StructuredTextParser RichTextLabel::_find_stt(Item *p_item) {
 }
 
 String RichTextLabel::_find_language(Item *p_item) {
-	Item *item = p_item;
-
-	while (item) {
+	String lang = language;
+	for (Item *item = p_item; item; item = item->parent) {
 		if (item->type == ITEM_LANGUAGE) {
 			ItemLanguage *p = static_cast<ItemLanguage *>(item);
-			return p->language;
-		} else if (item->type == ITEM_PARAGRAPH) {
-			ItemParagraph *p = static_cast<ItemParagraph *>(item);
-			return p->language;
+			lang = p->language;
+			break;
+		}
+		if (item->type == ITEM_PARAGRAPH) {
+			ItemParagraph *p = static_cast<ItemParagraph *>(item);
+			lang = p->language;
+			break;
 		}
-
-		item = item->parent;
 	}
-
-	return language;
+	return lang.is_empty() ? _get_locale() : lang;
 }
 
 Color RichTextLabel::_find_color(Item *p_item, const Color &p_default_color) {
diff --git a/scene/gui/spin_box.cpp b/scene/gui/spin_box.cpp
index 429040563e3..8edca6e2003 100644
--- a/scene/gui/spin_box.cpp
+++ b/scene/gui/spin_box.cpp
@@ -88,7 +88,7 @@ void SpinBox::_update_text(bool p_only_update_if_value_changed) {
 	double step = get_step();
 	String value = String::num(get_value(), Math::range_step_decimals(step));
 	if (is_localizing_numeral_system()) {
-		value = TS->format_number(value);
+		value = TS->format_number(value, _get_locale());
 	}
 
 	if (p_only_update_if_value_changed && value == last_text_value) {
@@ -137,8 +137,9 @@ void SpinBox::_text_submitted(const String &p_string) {
 	Ref<Expression> expr;
 	expr.instantiate();
 
+	const String &lang = _get_locale();
 	text = text.replace_char(';', ',');
-	text = TS->parse_number(text);
+	text = TS->parse_number(text, lang);
 	// Ignore the prefix and suffix in the expression.
 	text = text.trim_prefix(prefix + " ").trim_suffix(" " + suffix);
 
@@ -147,7 +148,7 @@ void SpinBox::_text_submitted(const String &p_string) {
 	if (err != OK) {
 		// If the expression failed try without converting commas to dots - they might have been for parameter separation.
 		text = p_string;
-		text = TS->parse_number(text);
+		text = TS->parse_number(text, lang);
 		text = text.trim_prefix(prefix + " ").trim_suffix(" " + suffix);
 
 		err = expr->parse(text);
diff --git a/scene/gui/tab_bar.cpp b/scene/gui/tab_bar.cpp
index 4c9c3f5ecef..31e6c669cf6 100644
--- a/scene/gui/tab_bar.cpp
+++ b/scene/gui/tab_bar.cpp
@@ -359,7 +359,8 @@ void TabBar::_shape(int p_tab) {
 		tabs.write[p_tab].text_buf->set_direction((TextServer::Direction)tabs[p_tab].text_direction);
 	}
 
-	tabs.write[p_tab].text_buf->add_string(atr(tabs[p_tab].text), theme_cache.font, theme_cache.font_size, tabs[p_tab].language);
+	const String &lang = tabs[p_tab].language.is_empty() ? _get_locale() : tabs[p_tab].language;
+	tabs.write[p_tab].text_buf->add_string(atr(tabs[p_tab].text), theme_cache.font, theme_cache.font_size, lang);
 }
 
 RID TabBar::get_tab_accessibility_element(int p_tab) const {
diff --git a/scene/gui/text_edit.cpp b/scene/gui/text_edit.cpp
index 2659d0b1755..cca2cb95b3a 100644
--- a/scene/gui/text_edit.cpp
+++ b/scene/gui/text_edit.cpp
@@ -39,7 +39,6 @@
 #include "core/os/os.h"
 #include "core/string/alt_codes.h"
 #include "core/string/string_builder.h"
-#include "core/string/translation_server.h"
 #include "scene/gui/label.h"
 #include "scene/main/window.h"
 #include "scene/theme/theme_db.h"
@@ -866,7 +865,7 @@ void TextEdit::_notification(int p_what) {
 		case NOTIFICATION_TRANSLATION_CHANGED:
 		case NOTIFICATION_THEME_CHANGED: {
 			if (is_inside_tree()) {
-				_update_caches();
+				_update_caches(p_what == NOTIFICATION_TRANSLATION_CHANGED);
 				_update_wrap_at_column(true);
 			}
 		} break;
@@ -1444,7 +1443,7 @@ void TextEdit::_notification(int p_what) {
 
 									Ref<TextLine> tl;
 									tl.instantiate();
-									tl->add_string(txt, theme_cache.font, theme_cache.font_size);
+									tl->add_string(txt, theme_cache.font, theme_cache.font_size, _get_locale());
 
 									int yofs = ofs_y + (row_height - tl->get_size().y) / 2;
 									if (theme_cache.outline_size > 0 && theme_cache.outline_color.a > 0) {
@@ -3357,7 +3356,8 @@ void TextEdit::_update_placeholder() {
 		placeholder_data_buf->set_direction((TextServer::Direction)text_direction);
 	}
 	placeholder_data_buf->set_preserve_control(draw_control_chars);
-	placeholder_data_buf->add_string(placeholder_translated, theme_cache.font, theme_cache.font_size, language);
+	const String &lang = language.is_empty() ? _get_locale() : language;
+	placeholder_data_buf->add_string(placeholder_translated, theme_cache.font, theme_cache.font_size, lang);
 
 	placeholder_bidi_override = structured_text_parser(st_parser, st_args, placeholder_translated);
 	if (placeholder_bidi_override.is_empty()) {
@@ -3403,7 +3403,7 @@ void TextEdit::_update_theme_item_cache() {
 	}
 }
 
-void TextEdit::_update_caches() {
+void TextEdit::_update_caches(bool p_invalidate_all) {
 	/* Text properties. */
 	TextServer::Direction dir;
 	if (text_direction == Control::TEXT_DIRECTION_INHERITED) {
@@ -3411,11 +3411,16 @@ void TextEdit::_update_caches() {
 	} else {
 		dir = (TextServer::Direction)text_direction;
 	}
-	text.set_direction_and_language(dir, (!language.is_empty()) ? language : TranslationServer::get_singleton()->get_tool_locale());
+	const String &lang = language.is_empty() ? _get_locale() : language;
+	text.set_direction_and_language(dir, lang);
 	text.set_draw_control_chars(draw_control_chars);
 	text.set_font(theme_cache.font);
 	text.set_font_size(theme_cache.font_size);
-	text.invalidate_font();
+	if (p_invalidate_all) {
+		text.invalidate_all();
+	} else {
+		text.invalidate_font();
+	}
 	_update_placeholder();
 
 	/* Syntax highlighting. */
@@ -3740,8 +3745,9 @@ void TextEdit::set_text_direction(Control::TextDirection p_text_direction) {
 		} else {
 			dir = (TextServer::Direction)text_direction;
 		}
-		text.set_direction_and_language(dir, (!language.is_empty()) ? language : TranslationServer::get_singleton()->get_tool_locale());
-		text.invalidate_font();
+		const String &lang = language.is_empty() ? _get_locale() : language;
+		text.set_direction_and_language(dir, lang);
+		text.invalidate_all();
 		_update_placeholder();
 
 		if (menu_dir) {
@@ -3768,7 +3774,8 @@ void TextEdit::set_language(const String &p_language) {
 		} else {
 			dir = (TextServer::Direction)text_direction;
 		}
-		text.set_direction_and_language(dir, (!language.is_empty()) ? language : TranslationServer::get_singleton()->get_tool_locale());
+		const String &lang = language.is_empty() ? _get_locale() : language;
+		text.set_direction_and_language(dir, lang);
 		text.invalidate_all();
 		_update_placeholder();
 		queue_accessibility_update();
diff --git a/scene/gui/text_edit.h b/scene/gui/text_edit.h
index a92dde1feb1..070e7549ebb 100644
--- a/scene/gui/text_edit.h
+++ b/scene/gui/text_edit.h
@@ -332,7 +332,7 @@ private:
 	Array st_args;
 
 	void _clear();
-	void _update_caches();
+	void _update_caches(bool p_invalidate_all = false);
 
 	void _close_ime_window();
 	void _update_ime_window_position();
diff --git a/scene/gui/tree.cpp b/scene/gui/tree.cpp
index 891ead7c328..3e46b0feb61 100644
--- a/scene/gui/tree.cpp
+++ b/scene/gui/tree.cpp
@@ -2105,7 +2105,8 @@ void Tree::update_column(int p_col) {
 	}
 
 	columns.write[p_col].xl_title = atr(columns[p_col].title);
-	columns.write[p_col].text_buf->add_string(columns[p_col].xl_title, theme_cache.tb_font, theme_cache.tb_font_size, columns[p_col].language);
+	const String &lang = columns[p_col].language.is_empty() ? _get_locale() : columns[p_col].language;
+	columns.write[p_col].text_buf->add_string(columns[p_col].xl_title, theme_cache.tb_font, theme_cache.tb_font_size, lang);
 	columns.write[p_col].cached_minimum_width_dirty = true;
 }
 
@@ -2174,7 +2175,8 @@ void Tree::update_item_cell(TreeItem *p_item, int p_col) const {
 	} else {
 		font_size = theme_cache.font_size;
 	}
-	p_item->cells.write[p_col].text_buf->add_string(valtext, font, font_size, p_item->cells[p_col].language);
+	const String &lang = p_item->cells[p_col].language.is_empty() ? _get_locale() : p_item->cells[p_col].language;
+	p_item->cells.write[p_col].text_buf->add_string(valtext, font, font_size, lang);
 
 	BitField<TextServer::LineBreakFlag> break_flags = TextServer::BREAK_MANDATORY | TextServer::BREAK_TRIM_START_EDGE_SPACES | TextServer::BREAK_TRIM_END_EDGE_SPACES;
 	switch (p_item->cells.write[p_col].autowrap_mode) {
diff --git a/scene/main/window.cpp b/scene/main/window.cpp
index 5d1694973cf..990837dd15e 100644
--- a/scene/main/window.cpp
+++ b/scene/main/window.cpp
@@ -32,7 +32,6 @@
 
 #include "core/config/project_settings.h"
 #include "core/debugger/engine_debugger.h"
-#include "core/string/translation_server.h"
 #include "scene/gui/control.h"
 #include "scene/theme/theme_db.h"
 #include "scene/theme/theme_owner.h"
@@ -2932,12 +2931,9 @@ bool Window::is_layout_rtl() const {
 				} else if (proj_root_layout_direction == 2) {
 					return true;
 				} else if (proj_root_layout_direction == 3) {
-					String locale = OS::get_singleton()->get_locale();
-					return TS->is_locale_right_to_left(locale);
+					return TS->is_locale_right_to_left(OS::get_singleton()->get_locale());
 				} else {
-					const Ref<Translation> &t = TranslationServer::get_singleton()->get_translation_object(TranslationServer::get_singleton()->get_locale());
-					String locale = t.is_valid() ? t->get_locale() : TranslationServer::get_singleton()->get_fallback_locale();
-					return TS->is_locale_right_to_left(locale);
+					return TS->is_locale_right_to_left(_get_locale());
 				}
 			}
 		}
@@ -2946,8 +2942,9 @@ bool Window::is_layout_rtl() const {
 			return true;
 		}
 #endif
+		const StringName domain_name = get_translation_domain();
 		Node *parent_node = get_parent();
-		while (parent_node) {
+		while (parent_node && parent_node->get_translation_domain() == domain_name) {
 			Control *parent_control = Object::cast_to<Control>(parent_node);
 			if (parent_control) {
 				return parent_control->is_layout_rtl();
@@ -2965,25 +2962,21 @@ bool Window::is_layout_rtl() const {
 		} else if (root_layout_direction == 2) {
 			return true;
 		} else if (root_layout_direction == 3) {
-			String locale = OS::get_singleton()->get_locale();
-			return TS->is_locale_right_to_left(locale);
+			return TS->is_locale_right_to_left(OS::get_singleton()->get_locale());
 		} else {
-			String locale = TranslationServer::get_singleton()->get_tool_locale();
-			return TS->is_locale_right_to_left(locale);
+			return TS->is_locale_right_to_left(_get_locale());
 		}
 	} else if (layout_dir == LAYOUT_DIRECTION_APPLICATION_LOCALE) {
 		if (GLOBAL_GET_CACHED(bool, "internationalization/rendering/force_right_to_left_layout_direction")) {
 			return true;
 		} else {
-			String locale = TranslationServer::get_singleton()->get_tool_locale();
-			return TS->is_locale_right_to_left(locale);
+			return TS->is_locale_right_to_left(_get_locale());
 		}
 	} else if (layout_dir == LAYOUT_DIRECTION_SYSTEM_LOCALE) {
 		if (GLOBAL_GET_CACHED(bool, "internationalization/rendering/force_right_to_left_layout_direction")) {
 			return true;
 		} else {
-			String locale = OS::get_singleton()->get_locale();
-			return TS->is_locale_right_to_left(locale);
+			return TS->is_locale_right_to_left(OS::get_singleton()->get_locale());
 		}
 	} else {
 		return (layout_dir == LAYOUT_DIRECTION_RTL);
diff --git a/scene/resources/3d/primitive_meshes.cpp b/scene/resources/3d/primitive_meshes.cpp
index f5886a8719f..e597caf4e4c 100644
--- a/scene/resources/3d/primitive_meshes.cpp
+++ b/scene/resources/3d/primitive_meshes.cpp
@@ -3226,8 +3226,9 @@ void TextMesh::_create_mesh_array(Array &p_arr) const {
 		TS->shaped_text_clear(text_rid);
 		TS->shaped_text_set_direction(text_rid, text_direction);
 
-		String txt = (uppercase) ? TS->string_to_upper(xl_text, language) : xl_text;
-		TS->shaped_text_add_string(text_rid, txt, font->get_rids(), font_size, font->get_opentype_features(), language);
+		const String &lang = language.is_empty() ? _get_locale() : language;
+		String txt = (uppercase) ? TS->string_to_upper(xl_text, lang) : xl_text;
+		TS->shaped_text_add_string(text_rid, txt, font->get_rids(), font_size, font->get_opentype_features(), lang);
 
 		TypedArray<Vector3i> stt;
 		if (st_parser == TextServer::STRUCTURED_TEXT_CUSTOM) {
@@ -3685,11 +3686,8 @@ void TextMesh::_bind_methods() {
 void TextMesh::_notification(int p_what) {
 	switch (p_what) {
 		case MainLoop::NOTIFICATION_TRANSLATION_CHANGED: {
-			String new_text = tr(text);
-			if (new_text == xl_text) {
-				return; // Nothing new.
-			}
-			xl_text = new_text;
+			// Language update might change the appearance of some characters.
+			xl_text = tr(text);
 			dirty_text = true;
 			request_update();
 		} break;