No loot from double bosses

I now had multiple instances with a double boss (necro+mastodon and double miller) which dropped no loot at all.

Because I found some other people having the same problem in the past I believe that this was either never fixed or the bug was recreated through one of the recent patches.

Edit: It might only happen if both die at the same time.

Same thing happen to me, only on double bosses and killed at the sametime.