Hard to say. You're already using the best graphics driver available. Maybe the problem is a RAM defect? Try running a memory test from your BIOS. Or you can make a bootable USB stick:
https://www.memtest.org/ https://www.memtest86.com/ -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to mutter in Ubuntu. https://bugs.launchpad.net/bugs/1878469 Title: Corrupt background and some corrupt icons [Intel Coffee Lake] To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1878469/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs