graphics – Display weirdness after update, PC unusable

Please forgive me if this is already covered somewhere, I’m using the Stack exchange app on my phone because my PC is unusable.

Today, I ran the usual updates Ubuntu provides me with, but when I turned the PC back on after shutting down, it started flickering after logging in. Sometimes it was the whole screen, sometimes the sidebar, and after at least a minute, I get kicked out onto the login screen. dmesg shows multiple context resets due to GPU hangs, whatever that means.

I already ran apt update and afterwards apt upgrade, but no luck.

What are your suggestions?