The kernel causing the problem is 5.4.0-42-generic. rolling back to 5.3.0-62-generic eliminated the problem.
-- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to nautilus in Ubuntu. https://bugs.launchpad.net/bugs/1888703 Title: After the latest update on 7/21/20 the screen shows random black horizontal single pixel line stripes in columns about 10-20 pixels long on open windows and icons presented on the desktop. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/nautilus/+bug/1888703/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs