In this old posting a problem was explained regarding graphical anomalies in the application. The poster was told by Parallels support to go to VM Configuration > Hardware > Video > Change to DirectX9 and disable Vertical synchronization. This was supposed to be for a macOS guest machine and so the DirectX9 part did not make sense, but even still, none of these configuration options are available now for Parallels 13 macOS guests. There is a "Graphics" configuration item and within that ONLY Memory is settable. Is there some other way to enable Vertical Sync or some other setting(s) necessary to resolve this graphical problem?