this bug don't let me switch between seats it's the second day it happens to me, yesterday in my tank and today with my harasser everything was fine but once the bug kicks in, i can spam as many vehicles i want none of them will let me switch seats no matter what i try nothing works quitting my game session for the second day cause of this bug
logging out and in usually fixes bugs like that. it sucks, but they're rare enough to not be a massive issue (it happens if you die while throwing down an ammo pack on engi, you can't place a turret or ammo pack until you relog.) also are you 100% sure it is an issue with the game? it could be your keyboard Fkeys messing up?