Bug in Login-Screen issue (double login of the same user possible - desktop gets useless for both logins)

[Erik Rull]

Hello,

I'm not 100% sure, but I think that the behavior is definitively unwanted:
- Start System (kubuntu 20.04 LTS - only one user available as set up during
installation)
- Log in as user "user"
- Lock screen
- Choose "switch user"
- Screen switching seems to happen
- Log in now as "user" (again - no other user can be chosen here)
- Log in seems to happen as for the first login, but no taskbar, autostart stuff
loads, when pressing Ctrl+Alt+F1 I get fractions of my previous login, but also
without taskbar, no real interaction with the GUI possible, etc. Pressing
Ctrl+Alt+F2 returns me to the "second" login, but this is still unusable.
- Way to get out: Either not using any gui until reboot (Ctrl+Alt+F3 => login,
sudo reboot) or sitting infinitely annoyed in front of two broken GUI logins...

The even more funny thing is: I didn't find that out initially, I just
accidentally entered my password on the second screen without having noticed
that the "switch user" was executed by my 15 month old son before... (Screen was
locked, he just randomly hit some keys on the keyboard and moved the mouse)

Best regards,

Erik