Not quite sure when it got bugged (it didn't start off this way to the best of my recollection). When you shoot the blitz needle at vana, if he smacks u in the face with his mace after your charge attacks end it freezes u in place (in a moronic gun up in the air stance) unable to move or remedy for a solid 1-1.5 seconds. It's a bit ridiculous. And a lesser point of contention with me on this is that it's a bug that effects gunners adversely and hasn't been addressed in a solid 3-6 months now.
Also, i'm pretty sure this happens anytime you get hit with a stun attack when it is time to reload with any gun. Your knight just stands there completely unable to perform any action (INCLUDING REMEDY!!!!).
Search up stun-lock