I think this issue is related to #3507 (changing resolution, display configuration via xrandr makes the main window's UI unresponsive).
@volca02 Yes, it is.
I was unable to reproduce this issue. I'm on Fedora KDE with AMD graphics.
Closing per the last comment.
Nothing extracted yet.
Steam UI becomes unusable after changing screen resolution or locking screen. It might be related with steamwebhelper (what is that?). Only tray icon is usable, and I can play games and use Steam overlay.
Arch Linux + Xfce + xfwm4 + nvidia