I don’t know the exact order of events that happened, but here goes.
I was in an itherian realm.
I completed a quest which spawned a portal, and I believe at the same time entered a battle with a nemesis creature.
Upon defeating the nemesis creature I was given loot for it.
The strange part was I was taken inside the itherian portal, but the boss and Umaro were missing.
The chests could be looted though.
When exitting the portal I was taken back to the castle.