Blank screen after update. (Xorg: No devices/screens found)

[5lood237]

@Fabby

If you have 5.10 LTS installed, add 5.4 LTS and boot into that and see if the problem goes away. If you have anything else, please advise and stop here!

sudo mhwd-kernel --install linux510

I have 5.11 rt, and booting into 5.10 via grub works fine.
What could be causing this issue in 5.11 rt?