### 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
EditorUndoRedoManager *ur = EditorUndoRedoManager::get_singleton();
	ur->create_action(TTR("Unpin Stylebox"));
	ur->add_do_method(this, "_unpin_leading_stylebox");
	ur->add_undo_method(this, "_pin_leading_stylebox", leading_stylebox.item_name, leading_stylebox.stylebox);
	ur->commit_action();
}
void ThemeTypeEditor::_unpin_leading_stylebox() {
	if (leading_stylebox.stylebox.is_valid()) {
		leading_stylebox.stylebox->disconnect_changed(callable_mp(this, &ThemeTypeEditor::_update_stylebox_from_leading));
	}
	LeadingStylebox leader;
	leader.pinned = false;
	leading_stylebox = leader;
	_update_type_items();
}
void ThemeTypeEditor::_update_stylebox_from_leading() {