Ultimatum ritual sacrifice does not work

Ultimatum "Sacrifice Monsters to the Altar by slaying them in the blood circles" is broken.
I stand in the blood circle for 5 minute straight killing mobs, it never completes.
It might be because they aren't awarding xp, and the game isn't flagging them as being killed.

I have encountered the same issue in 2 Inscribed Ultimatums in a row and had to abandon both. No matter how long, where, or how many monsters I kill in the circles, nothing seems to happen. They spawn continuously but will not progress the challenge.

Same thing happened to me

still same problem.. seems they dont really care.

+1

be aware that you have to stay inside the circles... (not (only) the monsters)

As Ebo_Ebo mentioned, you must stand within the circle itself the entire time or it doesn't count. Standing outside of the circle and just killing stuff will not advance the completion of each circle. I literally do nothing but run chaos runs non-stop when I play and I haven't run into this problem. If this is truly a bug there must be some additional factor here that I'm somehow not encountering.