Iron Citadel Instance Impossible to "Complete"

I have full cleared the entire map, but the monster remaining count is stuck at one. It appears Count Geonor is still showing as alive, despite being killed and his loot being collected. I suspect this was due to how fast he was killed.



This makes it impossible to "Complete" the map, resulting in a "Map Failed" notice when you move to the next map. This makes it so that you do not have access to connected nodes, meaning you must path around the Citadel node to continue in the Atlas.

This just happened to me too. I missed couple of rares mobs and went back to finished the map after killing the boss. Now it does not count as boss is dead.