### Godot version

4.1.1

### System information

linux

### Issue description

[simplescreenrecorder-2023-08-30_15.01.51.webm](https://github.com/godotengine/godot-proposals/assets/71937306/537d92b9-4f98-4fe6-adf4-71297be0471a)

I guess this wasn't the case before since I could save a layout named "2 monitors".

### Steps to reproduce

press space

### Minimal reproduction project

none
Variant value = leading_stylebox.stylebox->get(E.name);
		Variant ref_value = leading_stylebox.ref_stylebox->get(E.name);
		if (value == ref_value) {
			continue;
		}
		for (const Ref<StyleBox> &F : styleboxes) {
			Ref<StyleBox> sb = F;
			sb->set(E.name, value);
		}
	}
	leading_stylebox.ref_stylebox = leading_stylebox.stylebox->duplicate();
	
	edited_theme->_unfreeze_and_propagate_changes();
}
void ThemeTypeEditor::_type_variation_changed(const String p_value) {
	EditorUndoRedoManager *ur = EditorUndoRedoManager::get_singleton();
	ur->create_action(TTR("Set Theme Type Variation"));
	if (p_value.is_empty()) {
		ur->add_do_method(*edited_theme, "clear_type_variation", edited_type);
	} else {
		ur->add_do_method(*edited_theme, "set_type_variation", edited_type, StringName(p_value));
	}
	if (edited_theme->get_type_variation_base(edited_type) == "") {
		ur->add_undo_method(*edited_theme, "clear_type_variation", edited_type);
	} else {
		ur->add_undo_method(*edited_theme, "set_type_variation", edited_type, edited_theme->get_type_variation_base(edited_type));
	}
	ur->commit_action();
}
void ThemeTypeEditor::_add_type_variation_cbk() {