Since a few weeks I have a quite curious problem with logging into my system with SDDM to X Session Plasma. The problem is as follows: I have three monitors. The central monitor is being set as principal. When I start up the system, normally I logged into the plasma session via the principal screen (not that this is mandatory, but your eye focuses normally what is in front of you, not to the left or right). When I do input the password, SDDM accepts the input and freezes immediately as if the password would be wrong. But it also does not turn any error and does not return to the password prompt. Instead it stays kind of greyed out and frozen to any interaction. Now if I go the monitor left or right when this happens, then I can input the password, it is accepted and the session starts normally. By trial and error I d find out that the right and left monitor SDDM password is working, whether the first session opens, one user is already open or more user. But all tries to start a session on the central monitor (set in KDE as principal) fail. Now I tried to find any trace in the journal but nothing complains. All seems perfectly fine. So my questions: is there a special log that SDDM writes to? Does anybody has the same issue? Did anybody read about this issue on some bug list or mailing list? Somewhere I have to start, thank you.