Imprisoned Boss Bugged

The Imprisoned Boss is bugged after clearing the essence crystals around the boss and killing the boss. After killing the boss, I attempt to log out to character select. I then TP'd back to town and back in, still no atlas book drop as the map states. Map objective still states "Defeat the Imprisoned Boss".

Same issue for me, I cleared this map twice already, first time I used vaal on boss so my guess was that it didn't count because of that, this time I did not use anything, killed 4 essence mobs around the boss, then killed him but objective still says "Kill the Imprisoned Boss". My first map also shows as "failed" on atlas.

Same thing here,i only killed one essence pack then the boss and now i'm stuck

Same. Killed everything and empty map.

Add another. Same thing. Killed him, and nothing happens. Still with objective to defeat the imprisoned boss.

One more to this. I added a vaal and killed him. objective still says "defeat the imprisoned boss" and didn't get atlas skill book, boss is dead.

+1. Very annoying.

This just happened to me too. Maybe it's related to Vaaling the boss? I did it too.