### Godot version

4.0 beta 10, mono edition

### System information

Windows 11

### Issue description

No matter what I do Project Camera Override can never detect a game instance.

![image](https://user-images.githubusercontent.com/13719743/209912444-541f642a-42d3-4860-a4e0-54a17dbbab0b.png)

Of relevance: I can see remote nodes. I can see the output in the console. I can see the output in my IDE of choice (Rider). I can toggle debug mode.

It's just the camera that is unable to detect the game instance.

### Steps to reproduce

This happens everywhere, including on a brand new projects where the only nodes are a 2d camera and the Godot svg icon for testing. This also seems to happen when not using Rider as a third party editor.

### Minimal reproduction project

N/A
if (!root_node_selected) {
				desc += "\n" + TTR("Hold Shift when dropping to add as sibling of selected node.");
			}
			if (texture != nullptr) {
				Sprite2D *sprite = memnew(Sprite2D);
				sprite->set_texture(texture);
				sprite->set_modulate(Color(1, 1, 1, 0.7f));
				preview_node->add_child(sprite);
				label->show();
				label_desc->show();
				desc += "\n" + TTR("Hold Alt when dropping to add as a different node type.");
				label_desc->set_text(desc);
			} else {
				if (scene.is_valid()) {
					Node *instance = scene->instantiate();
					if (instance) {
						preview_node->add_child(instance);
						label_desc->show();
						label_desc->set_text(desc);
					}
				}
			}
			add_preview = true;
		}
	}
	if (add_preview) {
		EditorNode::get_singleton()->get_scene_root()->add_child(preview_node);
	}
}
void CanvasItemEditorViewport::_remove_preview() {