My friend and I were playing a tag match and this bug happened to both of us, it happened to him first, then me the second game. (I was using Arme and Jin, he was using Lass and Jin).
He killed my Arme, making my Jin come out ready to smash some face. But when I fully charged my rage bar Jin became immobile, only able to look left and right and use my pet, and appeared like he was being petrified but was not squirming. There is absolutely no way out of this except to leave the match, as you can not lose health. That's right, he's invincible to everything.
It doesn't happen every time, but there's definitely a reason why it does this. Not sure if it has anything to do with tag order, but I know for certain that this is a tag team bug.