### Godot version

4.0.beta12

### System information

Windows 11, RTX 3080

### Issue description

When a Window Node is created with it's Transparent flag set to true and Project Settings --> Display --> Window --> Subwindows --> Embed Subwindows is false, the Window has a black background. By cycling the transparent flag from false and back to true again, during runtime, the window's background then becomes transparent. 

### Steps to reproduce

Attempt to create a Non-embedded Subwindow with a transparent background using the appropriate flags. 

### Minimal reproduction project

Note: this project is from Reddit user [gongpha](https://www.reddit.com/user/gongpha/) and his Reddit post [Learning a Godot 4.0 Window node](https://www.reddit.com/r/godot/comments/xr8yxn/learning_a_godot_40_window_node/)

https://github.com/gongpha/godot4-window-test
IDC_SIZEWE,
		IDC_HELP
	};
	if (cursors_cache.has(p_shape)) {
		SetCursor(cursors[p_shape]);
	} else {
		SetCursor(LoadCursor(hInstance, win_cursors[p_shape]));
	}
	cursor_shape = p_shape;
}
DisplayServer::CursorShape DisplayServerWindows::cursor_get_shape() const {
	return cursor_shape;
}
void DisplayServerWindows::cursor_set_custom_image(const Ref<Resource> &p_cursor, CursorShape p_shape, const Vector2 &p_hotspot) {
	_THREAD_SAFE_METHOD_
	if (p_cursor.is_valid()) {
		RBMap<CursorShape, Vector<Variant>>::Element *cursor_c = cursors_cache.find(p_shape);
		if (cursor_c) {
			if (cursor_c->get()[0] == p_cursor && cursor_c->get()[1] == p_hotspot) {
				cursor_set_shape(p_shape);
				return;
			}
			cursors_cache.erase(p_shape);
		}
		Ref<Texture2D> texture = p_cursor;
		Ref<AtlasTexture> atlas_texture = p_cursor;
		Ref<Image> image;
		Size2 texture_size;
		Rect2 atlas_rect;
		if (texture.is_valid()) {