The title says it really - something to do with the way the screen climbs instantly and then resets gradually makes the recoil on the phosphor pistol cause motion sickness. It’s literally the only gun in the game that does it.
Please consider changing the gun’s recoil to be in line with others whereby the gun experiences the vast majority of the recoil, and not the player’s view. It would make the gun usable for those experiencing this.