### 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
} break;
		case ITEMS_TREE_REMOVE_ITEM: {
			String item_name = item->get_text(0);
			int data_type = item->get_parent()->get_metadata(0);
			EditorUndoRedoManager *ur = EditorUndoRedoManager::get_singleton();
			ur->create_action(TTR("Remove Theme Item"));
			ur->add_do_method(*edited_theme, "clear_theme_item", (Theme::DataType)data_type, item_name, edited_item_type);
			ur->add_undo_method(*edited_theme, "set_theme_item", (Theme::DataType)data_type, item_name, edited_item_type, edited_theme->get_theme_item((Theme::DataType)data_type, item_name, edited_item_type));
			ur->add_do_method(this, "_update_edit_item_tree", edited_item_type);
			ur->add_undo_method(this, "_update_edit_item_tree", edited_item_type);
			ur->commit_action();
		} break;
		case ITEMS_TREE_REMOVE_DATA_TYPE: {
			int data_type = item->get_metadata(0);
			_remove_data_type_items((Theme::DataType)data_type, edited_item_type);
		} break;
	}
}
void ThemeItemEditorDialog::_add_theme_type(const String &p_new_text) {
	const String new_type = edit_add_type_value->get_text().strip_edges();
	edit_add_type_value->clear();
	EditorUndoRedoManager *ur = EditorUndoRedoManager::get_singleton();
	ur->create_action(TTR("Add Theme Type"));
	ur->add_do_method(*edited_theme, "add_type", new_type);
	ur->add_undo_method(*edited_theme, "remove_type", new_type);
	ur->add_do_method(this, "_update_edit_types");
	ur->add_undo_method(this, "_update_edit_types");
	ur->commit_action();
}
void ThemeItemEditorDialog::_add_theme_item(Theme::DataType p_data_type, String p_item_name, String p_item_type) {