no Nameless seer on map

Mod allflame <Final Pack spawns the Nameless Seer on Death>, map Arachnid nest.
0 monsters remain, i look around ~20 times, and i can't find them. Maybe bug, idk.

I have gotten the same problem. We settled on the conclusion that since the mob i "put" nameless seer on is also contained in a legion, the mobs that didn't get killed and vanished somehow bugged the spawn. I am no expert to talk about this but he is definitely not in the map.

Same.

Very linear map underground river. 30 mins searching.
I got him 3 times in affliction so I know what he looks like.
Only mechanics that spawned in my map were expedition, torment and a vaal side area.

remember to use /debug while youre in the map and post that