I am currently experiencing some random screen flickering after a fresh install. I have a Lenovo laptop with Mesa Intel® UHD Graphics 620 (KBL GT2). It was working fine on 21.10.
A bug has been reported at Launchpad. If you're experiencing this issue, you can report it too.
Until it's fixed, this workaround worked for me:
sudo nano /etc/default/grub
In the grub file, I added to parameter GRUB_CMDLINE_LINUX_DEFAULT the value "i915.enable_dc=0 intel_idle.max_cstate=2". Then saved the file and run:
... to update grub. I did a reboot. I'm now flicker-free for ten days.
Had the same issue right after installing Ubuntu 22.04 on ASUS Zenbook also running the Mesa Intel® UHD Graphics 620 (KBL GT2) integrated graphics.
After searching for a couple of hours, I came across a thread suggesting adding the intel_idle.max_cstate=4 kernel boot parameter in /etc/default/grub as a workaround.
So far it seems to have solved the flickering issue.
Had the same issue with my dell inspiron-15-3567 got the fix by using acpi=off in /etc/default/grub but a new issue cropped up when shutting down system reaches shutdown target systemd-shutdown process-udevd is waiting so have to press down the power button . so have to choose between either screen flicker randomly or a shutdown issue