### Godot version

4.1 dev2, 4.0.3

### System information

Windows 10, ryzen 5900x, radeon 6950xt (driver: 23.2.2)

### Issue description

There are two bugs:
- When I create a new node, it is created outside of the viewport. (as in first video)
- When I run the project, all the content inside the viewport dont appear. (as in second video)
I believe the second issue is related to the first.

Note: these problems are in RTL editors.

https://github.com/godotengine/godot/assets/121864036/84f0d434-0d1b-4c23-9fb0-510257e2e191


https://github.com/godotengine/godot/assets/121864036/b2bc20c7-1e2e-4d04-99e7-d66860ffced2




### Steps to reproduce

Videos explain.

### Minimal reproduction project

N/A
} else {
				
				Viewport *viewport = get_viewport();
				ERR_FAIL_COND(!viewport);
				data.RI = viewport->_gui_add_root_control(this);
				get_parent()->connect(SNAME("child_order_changed"), callable_mp(get_viewport(), &Viewport::gui_set_root_order_dirty), CONNECT_REFERENCE_COUNTED);
			}
			data.parent_canvas_item = get_parent_item();
			if (data.parent_canvas_item) {
				data.parent_canvas_item->connect("item_rect_changed", callable_mp(this, &Control::_size_changed));
			} else {
				
				Viewport *viewport = get_viewport();
				ERR_FAIL_COND(!viewport);
				viewport->connect("size_changed", callable_mp(this, &Control::_size_changed));
			}
		} break;
		case NOTIFICATION_EXIT_CANVAS: {
			if (data.parent_canvas_item) {
				data.parent_canvas_item->disconnect("item_rect_changed", callable_mp(this, &Control::_size_changed));
				data.parent_canvas_item = nullptr;
			} else {
				
				Viewport *viewport = get_viewport();
				ERR_FAIL_COND(!viewport);
				viewport->disconnect("size_changed", callable_mp(this, &Control::_size_changed));
			}
			if (data.RI) {
				get_viewport()->_gui_remove_root_control(data.RI);
				data.RI = nullptr;