@fossfreedom Reinstalling/ updating didn’t solve the issue …
What caused the issue was using a corrupted icon package, Win10x. Maybe it wasn’t fully extracted.
The shortcuts you mentioned, CTRL+ALT+F3 / F7, to switch back and forth between the login screen and the TTY terminal put me on the right track to navigate to the folder and exclude the corrupted icon package from my /.icons directory.
That brought the system back.
Thanks for looking into this … it is good to learn something every day.