It does sound like a stressed VPU (overheating), especially if it's intermittent.
Next time you get a chance, the first time of the day you begin to play (when the PC/VPU is cold), see if they do not happen the first 10 minutes you play, but grow more frequent the longer you play.
If it's not heat, try to see if there's some pattern to when they show up,like only in exterior view, or a particular texture is showing. That would indicate a driver problem.
__________________
|