Duo boss's drop no loot when killed same time!

I'm running a poison build which causes both bosses to die same time usually and they don't drop loot. I made sure to toggle my hide loot button and disable my filter. They actually drop nothing. This happened in the ske trial with two giants ice/fire. Again on a tier 5 map where it had a boss icon meaning it should level up my waystone tier. The duo boss was the first troll boss died same time not even the waystone dropped. Please look into this, I will try to record more often to catch this in the act.

Yep Same thing just happen to me on 2 double boss maps in a row. Also running poison build with same outcome.