Was doing the legendary campaign and encountered a soft lock. In the second to last fight in the mission "The Ritual" I had two of the Lucent Hive (Acolyte & Knight) fall off the map near the lily pads in the front of the arena. This prevented the trigger for the main boss' health gate to complete and resume the fight. The Lucent Hive did not respawn and their ghosts were no where to be found on the shore to crush. So I had to jump off the map to reset the instance and continue. Fairly frustrating because that fight took several attempts solo and finally having something go right just for it to backfire was disappointing.