Elder Guardian Eradicator Bug

Hey,

a mate and I recently tried to kill the Eradicator on a T13 Defiled Cathedral map.

This bug happened every time we tryed to kill the guardian:

Once in his "unkillable phase" where he transform into the lightning tendril thingy, he gets stuck at his cast location and repetetdly casts his "spell" resulting in having many many of his unkillable forms (as seen in the pictures below).

Once dead (every thingy deals damage) trying to rejoin the instance fails.

Fight 1


Fight 2

Best regards