macOS: Window shown from dispatcher shows blank

[grokys]

Describe the bug

On macOS, showing (but not creating) a window inside a dispatcher callback results in a blank window.

To Reproduce

The following code in a Window codebehind reproduces the behavior:

protected override void OnPointerReleased(PointerReleasedEventArgs e)
{
    var window = new Window();
    Dispatcher.UIThread.Post(() =>
    {
        window.Content = "Hello";
        window.Show();
    });
}

If one moves the var window = new Window(); inside the dispatcher callback then the window shows correctly.

Expected behavior

No response

Avalonia version

master

OS

macOS

Additional context

No response