No Itherian Boss

0.10.8

I was pressing E when exiting a greedy nemesis fight, eager to get the loot, but I guess I was in front of and facing the portal to the itherian boss room. I immediately entered the room and the loot from the nemesis popped up when in the boss room. However, there was NO itherian boss. I was able to loot both treasure chests, but no Umaro to upgrade my talisman.