### Godot version

v4.2.dev3.official [013e8e3af]

### System information

Windows 10, 64bit

### Issue description

![image](https://github.com/godotengine/godot/assets/35988767/ccdac68c-a60d-491b-a406-d6e3bc1c95ae)
![GIF](https://github.com/godotengine/godot/assets/35988767/7d230faf-0260-4bc3-92e8-11cd026931a8)


### Steps to reproduce

/

### Minimal reproduction project

/
switch (p_what) {
		case NOTIFICATION_ENTER_TREE: {
			
			if (get_tab_count() > 0) {
				_refresh_tab_names();
			}
		} break;
		case NOTIFICATION_READY:
		case NOTIFICATION_RESIZED: {
			_update_margins();
		} break;
		case NOTIFICATION_DRAW: {
			RID canvas = get_canvas_item();