### 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 Theme::DATA_TYPE_MAX:
			return; 
	}
	updating_tree = true;
	for (List<TreeItem *>::Element *E = item_list->front(); E; E = E->next()) {
		TreeItem *child_item = E->get();
		if (!child_item) {
			continue;
		}
		child_item->set_checked(IMPORT_ITEM, true);
		child_item->propagate_check(IMPORT_ITEM, false);
		_store_selected_item(child_item);
	}
	updating_tree = false;
}
void ThemeItemImportTree::_select_full_data_type_pressed(int p_data_type) {
	ERR_FAIL_INDEX_MSG(p_data_type, Theme::DATA_TYPE_MAX, "Theme item data type is out of bounds.");
	if (updating_tree) {
		return;
	}
	Theme::DataType data_type = (Theme::DataType)p_data_type;
	List<TreeItem *> *item_list = nullptr;
	switch (data_type) {
		case Theme::DATA_TYPE_COLOR:
			item_list = &tree_color_items;
			break;
		case Theme::DATA_TYPE_CONSTANT:
			item_list = &tree_constant_items;
			break;