Ubuntu 20.04 LTS Screen Refresh / Flickering Issue

Question

Recently upgraded from Ubuntu 19 to 20.04, since doing so I keep running into an issue that I struggle to describe so here goes...

Initially, right after login, the screen will re-size / flicker - it is most noticeable with Plank which moves around on the screen.

Screen flicker Plank duplication Fade out

What will happen as time goes by is I will be in an application and the screen will reload, best way to describe it is an application is minimized and then is maximized and then is minimized and so on.

At this point the system is basically unusable because I can't stay in a single app for long enough to do anything.

This is on a Lenovo T440s laptop. I don't seem to have any additional display drivers to install but could it be a driver issue?

I did see a post that read similar to my issue:

Ubuntu 20.04 LTS Screen Flickering Lenovo Yoga S740 Geforce MX250

But it happens on power and battery, I've removed TLP

If I can provide additional details please let me know.

Any ideas?

Thanks, Andrew.

Answer 1

**** Determine the actual problem - the re-installation of gnome seemed the solution but the only reason it worked was because it disabled everything I had running. Turns out that the root cause was due to the Gnome extensions, specifically the Wifi signal strength monitor which was set to refresh every 10 seconds and coincided with the screen refreshing. Once disabled my issue went away.**

OK I think I solved my issue... I'm still not sure exactly what caused it but a fix is a fix.

What I noticed was if I switched between gnome and budgie the issue didn't not happen in budgie. That lead me to believe something was corrupt / clashing / broken in gnome so based on the following thread:

How to remove and reinstall GNOME 3?

I followed: https://askubuntu.com/a/1034227/1084966 and once the reinstall had completed my system has gone back to working exactly as expected.

Thank you to the community for all the knowledge and information.