Flickering and Screen freezes

Running Byzantium on my Librem15rev3, every now and then (often when I am switching between Workspaces, but not always) I experience screen freezing. Audio streams continue, but I can’t move the mouse or keyboard. When I close the lid, the laptop goes to sleep (suspends) after some time. Depending how long it stays that way, it either wakes up with the same frozen screen, or (after a longer period of sleeping) comes back with the unlock screen.

Another thing I notice is that when I reboot the laptop, the screen will be flickering until I put it into “suspend” for a brief time, after that it will function normally.

After reading this post https://puri.sm/posts/update-on-librem-ec-1-12/ , I am wondering if this could be related to the setting of power limits? How could I verify this? Can this be logged somehow?

Pretty sure that post is intended to be and is applicable only to the Librem 14. (I think that the EC is not even updatable by Purism on the Librem 15.)

That is pretty strange. If there are graphical issues, that means dom0 may be affected. I suggest a fresh installation of Qubes OS, but make sure to back up any important files beforehand.