Not getting atlas points from clearing corrupted nexus

playing on 0.4.0 league. I just entered my first corrupted nexus map (tier 3 5 mods). I initially died to the boss and then respawned and killed the boss. The corrupted boss did not spawn and the map says "complete". The surrounding atlas maps are sanctified, but I did not get a book for atlas points from Doryani and the quest still says "travel to the corrupted nexus".

Need help on how to proceed.