I have the same issue with HDR in this game. It just randomly goes to desktop randomly and fairly often.
My daughter playing on her PC and a completely different display would get lots of crashing with HDR enabled. She never had it just go to desktop with the ability to alt tab back to the game…it would just crash.
So I keep HDR turned on because I love HDR and I don’t have any crash issues with the game but until they fix it she’s unfortunately keeping HDR off.
Lots of weird issues in this game…ones that really shouldn’t exist and I think some of them are definitely being caused by denuvo. So once again the paying customer gets punished the most.