I am running Parallels 19.1.1 on my Sonoma MacBook Air M1 so that I can access a Windows 11 virtual machine. In addition to the native monitor of the MacBook, I use an external monitor (Samsung 32") in extended display mode. I open the Windows 11 virtual machine on the external monitor. Periodically the Windows 11 VM 'moves' from the external monitor to the native MacBook Air monitor. The external monitor is still connected as an extended display because I can see that the wallpaper that it is displaying is the wallpaper that I have defined for my Macbook. Macbook is always powered from then power adapter. In Lock Screen settings, "Turn display off on power adapter when inactive" is set to "Never" In the Windows 11 Power & battery dialog, all the Screen and sleep settings are set to "Never" so Windows never puts the machine to sleep and never turns off the screen. Tried both with and without Coherence Mode, but get this problem with both view settings. How can I prevent the Windows 11 VM jumping from the extended display monitor to the native monitor? What am I missing?
I beleive that I have solved the problem. I was using an Apple Multiport adapter and it would seem that the USB connecter was faulty, which was causing intermittent disconnection of the adapter, and hence the monitor. No problems since I started using a third-party (UGreen) adapter.
