### 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
case Theme::DATA_TYPE_MAX:
						break; 
				}
			}
			new_snapshot->set_theme_item(ti.data_type, ti.item_name, ti.type_name, item_value);
		}
		idx++;
	}
	
	ProgressDialog::get_singleton()->task_step("import_theme_items", TTR("Updating the editor"), idx++);
	
	ProgressDialog::get_singleton()->task_step("import_theme_items", TTR("Finalizing"), idx++);
	ProgressDialog::get_singleton()->end_task("import_theme_items");
	EditorUndoRedoManager *ur = EditorUndoRedoManager::get_singleton();
	ur->create_action(TTR("Import Theme Items"));
	ur->add_do_method(*edited_theme, "clear");
	ur->add_do_method(*edited_theme, "merge_with", new_snapshot);
	ur->add_undo_method(*edited_theme, "clear");
	ur->add_undo_method(*edited_theme, "merge_with", old_snapshot);
	ur->add_do_method(this, "emit_signal", SNAME("items_imported"));
	ur->add_undo_method(this, "emit_signal", SNAME("items_imported"));
	ur->commit_action();
}
void ThemeItemImportTree::set_edited_theme(const Ref<Theme> &p_theme) {
	edited_theme = p_theme;
}
void ThemeItemImportTree::set_base_theme(const Ref<Theme> &p_theme) {
	base_theme = p_theme;
}
void ThemeItemImportTree::reset_item_tree() {