Technically, https://en.wikipedia.org/wiki/Virtual_reality_sickness, but I think motion sickness suffices as a generic term.

I also think discriminating between motion sickness, flight simulator sickness and virtual reality sickness is splitting hairs, or at least a gradual difference. One could claim motion sickness requires real motion, but you have that in a good flight simulator, too, and most VR setups allow one to, at the least, move one’s head freely.