Can't change screen locking wallpaper in Maui 17.03

[RealPTR]

Looks like a graphical glitch. Tried resizing or moving the window already ?
Anything useful on the terminal when started from the terminal ?

Yes - tried moving or resizing the window. No change. Also clicking buttons inside the "glitched" area brings no action. But clicking in the side menu does what it should (take you to another panel of settings).

Terminal prints this after clicking "display":

Code:

$ systemsettings5
kscreen.kcm: LOAD
kscreen.kcm: Activate output 67

And nothing else after cliking further: Screen Locking -> Wallpaper