Dragging a window to an edge of a screen turns the snap-to point bright white despite my theme being Breeze Dark.
I’ve only noticed this after the recent qt update (6.10.2-1 → 6.11.0-1)
Same issue here. I was replacing vlc with mpv, and then this happened. I realized I had broken the system somehow, yet even after a rollback the issue persisted. Reading this, I do remember that I had performed a system upgrade beforehand, and it included qt updates.
Rolling back to a snapshot prior to the upgrade clears the issue.