### 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
select_all_font_sizes_button = memnew(Button);
	select_full_font_sizes_button = memnew(Button);
	total_selected_font_sizes_label = memnew(Label);
	select_icons_icon = memnew(TextureRect);
	select_icons_label = memnew(Label);
	deselect_all_icons_button = memnew(Button);
	select_all_icons_button = memnew(Button);
	select_full_icons_button = memnew(Button);
	total_selected_icons_label = memnew(Label);
	select_styleboxes_icon = memnew(TextureRect);
	select_styleboxes_label = memnew(Label);
	deselect_all_styleboxes_button = memnew(Button);
	select_all_styleboxes_button = memnew(Button);
	select_full_styleboxes_button = memnew(Button);
	total_selected_styleboxes_label = memnew(Label);
	for (int i = 0; i < Theme::DATA_TYPE_MAX; i++) {
		Theme::DataType dt = (Theme::DataType)i;
		TextureRect *select_items_icon = nullptr;
		Label *select_items_label = nullptr;
		Button *deselect_all_items_button = nullptr;
		Button *select_all_items_button = nullptr;
		Button *select_full_items_button = nullptr;
		Label *total_selected_items_label = nullptr;
		String items_title;
		String select_all_items_tooltip;
		String select_full_items_tooltip;
		String deselect_all_items_tooltip;
		switch (dt) {
			case Theme::DATA_TYPE_COLOR:
				select_items_icon = select_colors_icon;