Ritual not ending despite killing all mobs

Bug Report ID 2957132206

Ritual spawned in a tight corridor, killed mobs, ritual did not end. I made sure to walk over every pixel in case mob is in ground to make it appear, no change. Used mana tempest to try to chain to nearby mobs over entire floor of ritual arena, no change.

3 months later this is still happening.
Area is mainly an open area, sump map.
I moved to every spot and no mobs spawning anymore.

Relogging like mentioned on reddit doesn't end it.