Cathedral of Light Capstone dungeon progress is blocked

Hello, I am doing a capstone dungeon to open World Tier 3. In the last phase, where all enemies must be slain, I have (1 remaining) that is not visible on the map. I did TP to Kyovashad and when I came back the NPC was not in the dungeon anymore… Which means that I can’t progress to the final phase as I am still with 1 remaining and nothing to kill.
Trying to go to every single corner and wall and there is no mob that is spawning, even a ghost one. Please look into this bug!