Parallels 15.1.4 macOS 10.15.5 My Windows 10 guest today was behaving strange. When two finger wiping to the Windows VM, I suddenly saw a split screen, Windows 10 on the left half, an Apple mail app client window showing a sending error asking for confirmation to try again or later. When terminating the right half of the split screen, the Windows 10 screen did not come back. Instead a white garbage stripe was shown. Somehwo I got the Windows screen back but Windows 10 was showing only in a narrow stripe in the middle of the screen, kind of "portrait format". I only got back to the normal Windows 10 login screen after stopping and restarting Windows. Embarrassing somehow..