Separate names with a comma.
EDIT3 (sorry :)): a fresh standard installation of Mint 20 including Parallels Tools installation of course
EDIT2: We have narrowed it down a bit... This is how it's reproducable and what we followed for testing purposes:...
EDIT: VNC obviously doesn't completely stop working, it just seems as if the client wouldn't have sufficient rights to display the screen; cursor...
Same here: Parallels Tools (PT) not installed, VNC works (tightvnc, tigervnc or X11vnc; all flavours)/ PT installed -> VNC stops working/ PT...
Same problem here with Debian Buster and ffmpeg unfortunately..