Shortly after installing Ubuntu 18.04 in my computer I noticed that very frequently and without any apparent reason the desktop and specially Google Chrome windows (although not exclusively) start flickering, like momentarily showing windows that are behind it.
I recorded a short GNOME screencast.
You might notice that GNOME is very heavily themed, but the error started happening before they were installed (I've been trying to find the problem for a while now). I even changed kernels afterwards, without any change (I had to patch-in compatibility for my touchscreen).
This is an HP Envy X360, running at full 1080p. I suspect it might be related to the AMD drivers (native Radeon R7).
Any ideas for debugging or any fix? I can't even describe the glitch properly so I haven't had any good luck with Google.