Nameless seer not spawning

The Belly of the Beast level 2 didn't spawn my seer :(
I don't know the name of the monster but it was the last one in the list of monsters and /remaining says 0 i ran around the entire map 3 times checking and nothing
so sad i could of used that as I just started SSF

here is a link to video proof of no seer spawning
https://youtu.be/WyjcwV0Bxx8

I'm having the same issue. Had him twice this league and both times he didn't spawn with 0 monsters. No side content like Lab/Harvest/Vaal area or anything. Made sure he was top of the lantern. Checked the whole map multiple times and had others come look as well.

Yeah feels very bad when this happens hopefully they fix it

it just happened to me on dunes. i've had him before a few times so I know what he looks like. I also put on some super zoomy gear so I could thoroughly check the map and I know for certain he didn't spawn.

i'm not sure if this has anything to do with it, but I entered a betrayal research area before killing the final pack...maybe that's irrelevant, but I went back in and checked every room to make sure I didn't leave any monsters or missed him in there. yeah, I don't know what causes this problem or if it can be fixed, but just to be super safe in the future I'm not going to enter the research area until I clear all the monsters.

Final pack spawns the nameless seer on death.
0 monsters remaining and hes not in the map. I do run back to basic, not sure if it removes the seer or not.

update: got him in another map with back to basic so was just bug first time.