I have installed Ubuntu 19.10 on an system with a radeon graphics card. It worked fine the first time I booted it up, but every time after that I just get a black screen after entering my password. I tried nomodeset in grub, but that doesn't seem to help. Trying to log into a wayland session just freezes on a purple screen instead of a black one. I can press ctrl-alt-F2 to get into a terminal from the log in screen, so I'm not completely locked out of the system.
What should I do to get things back up and running?
If it helps, I installed the /home folder on its own partition, so I could reinstall without losing everything.