(Debian 12 as OS, SCID 5.0.2) Current bug:
After clicking some UI elements, like pieces on the chessboard, or other buttons, I can't properly focus anymore on the textfield to type into (in other words: I click a textfield and try to write some text into, but it does nothing and the text cursor is not visible either). At first glance, there is apparently no way to solve this issue inside the program, although this issue "disappears" after switching windows (e.g. double alt-tab) coming back to SCID.
I use this program as well on Ubuntu 22.04 LTS and Windows 11, and on none of those there is this issue.
Sometimes the notation window as well doesn't take anymore keys in input; it is like the keyboard input gets detached for some reason and the application just doesn't accept to receive key inserts. Even here, the issue disappears after switching focused windows and going back on SCID.
The application is overall still usable (there's nothing I can't do) but this workaround may need to be done several times so it makes the application more frustrating to use.
The problem apparently disappeared after properly installing Nvidia drivers (which was not easy to do due to Secure Boot). I am not sure that's strictly the cause but it's the only thing I did. I also blacklisted Nouveau driver doing so.