Hi, just wanted to leave an update on my issue after the last update 2021-11-19, in case anyone is still encountering the same problem. The issue was that after the update GDM crashed with a Segfault on startup. However, it worked when started manually from command line.
This was my original report:
I worked around it by installing lightdm with lightdm-slick-greeter. Additionally I had to apply this patch to make it work with my graphics card: