Intense screen flickering, vertical rainbow bars, display problems on Ubuntu 20.04, Lenovo X1 Carbon

Starting today (Aug 24) I observed intense screen flickering and tearing on my Ubuntu 20.04.3 on the Lenovo X1 Carbon. As far as I know, there were no shutdowns, updates, or changes. I observed this behavior once the machine started up from sleep. Throughout the day I have restarted (and powered down) the machine several times, but the problem persists.

Here is a video example: https://photos.app.goo.gl/516nAe7AUUYnAHzd7

Here is an image: cant embed pictures yet :(

This video was taken from a clean Ubuntu install USB, so I don't think it has to do with anything I've installed or updated in the past. The system does not have any other operating systems on it (its not dual booted).

I'm using basic integrated graphics (Mesa Intel® UHD Graphics 620 (WHL GT2)). System has 16gb of RAM and a Intel® Core™ i7-8665U CPU @ 1.90GHz × 8 processor, so I don't think the issue is available processing power (although the integrated graphics could be bad).

I'm already using Wayland.

I tried everything in the following links: Ubuntu screen flickering https://www.reddit.com/r/Ubuntu/comments/g78o4e/screen_tearing_in_ubuntu_2004/

The flickering is most noticeable in Chrome/Firefox (regardless of enabling/disabling hardware acceleration or setting any chrome://flags). However, I've also observed it with just editing Vim in terminal.

Not sure what else to try, or how to debug. Would appreciate any help.

EDIT: A month later, still experiencing this issue. This problem really seems to come and go -- it will go days without issue, and then have days again where it is constant. I've noticed it on all browsers. I've noticed that closing the webbrowser seems to resolve the issue most of the time. I've noticed that this is not an issue on any extended screens, just the main screen.

EDIT: Launchpad bug filed here: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1950355

First of all this doesn’t look like tearing to me. It’s a graphical issue but likely not tearing. That is why Wayland probably didn’t help.

It looks more like a gpu related issue. Recently 20.04 should have gotten an update to 20.04.3 which includes a newer Kernel and Mesa GPU drivers. If possible can you find an older Ubuntu ISO of 20.04.2.0 and try run that on a live USB? If the issue is introduced on your install with 20.04.3 please report a bug at bugs.launchpad.net.