On Tauti stage after first jump he bug on center and don't attack and stay also no1 from party member cant target him and ofc cant finish the instance
i have encountered smtg like that in NmKama: Sirra, the 4th RB, don't retaliate, but i was able to target and hit( minions act normal) and in lower Giant's Cave Shaqrima Kshana do nothing when i kill other mobs around, or i hit him.