I have the same problem on that kernel (ubuntu 20.10), and on the update to 5.8.0-50.55. I have gone back to 5.8.0-48.54 and it has stabilised. I get all sorts of different effects. Blocks of text being partially blank, whole menu boxes being blank, and so on. This usually happened after the system has been on for a few hours, so I initially suspected hardware, but reverting to 5.8.0-48 fixed it.
The worst effected are browsers (Firefox, Chrome and Brave) possibly only when not full screen, but parts of the application icon toolbar and others parts flicker on and off as well. I tried wayland, but it was no better, so an x.org update may not help (I can't see one available at present) I'm using "Intel® HD Graphics 4600 (HSW GT2) graphics", on "Intel® Core™ i7-4770T CPU @ 2.50GHz × 8". No special drivers. Monitor connected via HDMI. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1923632 Title: Screen flickering To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1923632/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
