It happens sometimes when I alt+tab away from osu and then come back to it. I haven't found a reliable way to reproduce it, it seems pretty random, but it always happens that way and is fixed by just moving the mouse.Looks like the rough size of the bounding box my cursor was stuck in (maybe a bit smaller) when alt-tabbing out sometimes. It was random outside fullscreen osu!, and had 100% chance of happening in editor. Though, I didn't get any graphical anomalies you got. Also haven't found a way to reproduce since last time I restarted osu!.