Silent Cave Boss Bugged out and is uninteractable.

Was trying to clear a 6 mod, 15+ waystone Silent Cave. Upon killing the 4th Essence trapped mod the ability to interact with the final boss disappeared.

I can't click on the mob either to break it out. Tried logging out and back in. Tried going to each of the lesser mobs to see if one was maybe burrowed and nothing came out at any of the other 4 sites.

https://imgur.com/a/gQbODgk