I deleted my save and started again. It very nearly happened again, but I recognised the signs and stopped everything I was doing until it settled down (wasn’t possible first time, as I was in a vehicle that was bouncing off a hill at the time) and now I’ve managed to get to phase 2.
I’ve been a bit confused though because visually it genuinely doesn’t look any better than psvr. It’s specifically NMS related and I’m wondering if there’s been a mistake in the update. It’s decently causing people issues, but it’s really not the high res FSR 2 experience I was expecting.
Just checked Reddit and it seems like a very common complaint specifically about NMS.