No loot on killing boss and boss not registered as killed

Happened on a endgame map. Entered the boss arena, was a boss that was summoned into the arena, and after killing it no loot dropped (double checked hitting ALT) and the boss fight wasn't registered as completed. This meant I couldn't portal out or exit the arena. Had to quit to character select and go back to the map via portal. Also if you reentered the arena it would trap you again. Unfortunately not recording or pictures of it.

I just had this happen to me too.

On Tier 8 Sulphuric Caverns map as a Titan, cleared the rares and entered boss arena. It was the skull mammoth, used Shield Walls to build up rage, Infernal Cry to Enpower, and then dropped Hammer of The Gods.

Boss was killed in one hit and didn't drop any items. Game still thinks I'm in the boss fight and won't let me leave the arena or teleport out of there. I log out and re-enter the map from hideout to find boss arena. Enter boss arena to see that boss is still dead and bugs out on me the same way again.

Not sure how to post pics/vides but I have a couple.