Unable to switch user/account

[supiik]

After upgrade to 20.04 from 19.10 using Raspberry PI4 I am not able to switch users.
I have three users. I am experiencing following:
1. complete freeze - only restart helps - I can see purple screen with the list of users but I am not able to move with cursors, I am not able to use keyboard, I am not able to use terminal.
2. I see black screen with cursor - see attachment. I can switch to console, I can press ALT CTRL F3 and login same user which was logged in before.

Please tell me what debug info do you need and how to get it.

[supiik (peter-iring)]

It is possible to move with cursor but there is nothing to click at.

[supiik (peter-iring)]

Yes, it is.
Last days the behavior changed a little.
Few days ago this happened to me all the time and was pretty easy to reproduce. These days it is like 1:10 that it happens.
Right now I am able to switch to console and one of these help - I tried all of them because I was desperate:
sudo systemctl restart gdm
sudo systemctl restart lightdm
sudo dpkg-reconfigure lightdm

When one of these commands help, I see standard login screen with list of users and I am able to switch the one I need.

Peter

[Martin Wimpress  (flexiondotorg)]

This was fixed in Ubuntu MATE 21.10 with the introduction of arctica-greeter-guest-session