Flickering ghost images may be caused by gnome-shell's damage tracking losing track of where things have been drawn, and it then uses buffer age information incorrectly, leaving junk in only one of the buffers (out of 2 or 3). So every second or third frame contains pixels that shouldn't be there, 20 or 30 times per second. I think the best way to work around it is to drag a window over the flickering area.
Also, please report this bug to the Gnome developers here: https://gitlab.gnome.org/GNOME/mutter/issues -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-shell in Ubuntu. https://bugs.launchpad.net/bugs/1770731 Title: [nvidia] multimonitor ghostly flickering display artifacts To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1770731/+subscriptions -- desktop-bugs mailing list firstname.lastname@example.org https://lists.ubuntu.com/mailman/listinfo/desktop-bugs