Strange problem, systemctl suspend gave the same problem.
I’ve tried to modify KDE options : configuration > space behavior > screen lock > appearance
No more problem with suspend.
Now I’ve tried with systemctl hibernate and all is fine.
I suspect a problem with the lock screen dialog (but I don’t remember to have changed it since many weeks).
I’ve updated my kernel to 6.6.8 (again) and there is no more problem.
I’ve uncommented my autofs mount and all is fine.
The login problem is solved and the launcher bug has disappear.
Applying a theme could be a solution to clean up some KDE configuration problem