[BaronNightmare]

I had a similar problem, but it was when I accidently resized the window(I was trying to click something off the window and clicked the edge and moved it less than a cm), but on UN.

The graal window went all black then a few seconds later it returned to the graal image and when I started walking everything was making trails like that.

I had to close graal and relogon for it to go away when it happened to me. As I stated though it happened on UN, specifically in their main spar room.