So the fight with Bishop Alexander and the Voidwoken Worm in Act 1 is sometimes bugged.
When me and my friends fought, the Worm spawned in a rather tight area and the Metamorph and BA went to fight it. But as they were standing there, all thee right next to each other, the MM didnt do anything, no attack or even a buff, same with the Worm. BA at least did Staff of Magus but they just stood there, passive.