### 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
if (!leading_stylebox.pinned || leading_stylebox.stylebox.is_null()) {
		return;
	}
	ERR_FAIL_COND_MSG(edited_theme.is_null(), "Leading stylebox does not have an edited theme to update");
	
	edited_theme->_freeze_change_propagation();
	List<StringName> names;
	edited_theme->get_stylebox_list(edited_type, &names);
	List<Ref<StyleBox>> styleboxes;
	for (const StringName &E : names) {
		Ref<StyleBox> sb = edited_theme->get_stylebox(E, edited_type);
		
		if (sb == leading_stylebox.stylebox) {
			continue;
		}
		if (sb->get_class() == leading_stylebox.stylebox->get_class()) {
			styleboxes.push_back(sb);
		}
	}
	List<PropertyInfo> props;
	leading_stylebox.stylebox->get_property_list(&props);
	for (const PropertyInfo &E : props) {
		if (!(E.usage & PROPERTY_USAGE_STORAGE)) {
			continue;
		}