I've had it happen before too but I'm on a 5700 AMD card. Previously it's been a blank screen and crash to desktop. Now it's more rare but sometimes halts the entire system itself.
My best guess is that it's a GPU panic/driver crash. These types of problems are very hard to diagnose however without a lot more info/logs. Sadly, I never found much of interest in the event logs, and there was no crash log as the system halted.
I should mention I'm also on a new machine, 3600x, 16GB RAM. Played RDR2 on ultra with no crashes so I think it's M&B specific.