Wayland: Blurring title bar and freeze

[DonKatsu]

After centering a window with Meta+C, the title and controls become blurred. Moving the window fixes it, but resizing the window doesn't.
If I resize the window too much while the title bar is blurred, the entire display freezes. Audio continues to play, but I can't even switch TTYs. CPU ramps up during this.
Example.

KDE Version: 5.26.5
KDE Frameworks Version: 5.102.0
Qt Version: 5.15.8
Display Driver: Mesa

Judging by the activity on this script, I assume Wayland isn't exactly tested.
I also suppose this should be reported on the KDE bug tracker, but my journal doesn't seem to have anything after the point where the freeze occurs so I'm not sure where to start.