Boss with loot disappeared

Good evening!

On December 21, 2014, I and random players ended up in the Black Morass dungeon. We killed Temporus, the accessory dropped - Hourglass of the Unraveller. But unfortunately, it was not possible to pick him up because the boss’s body disappeared during the roll.

My pain cannot be expressed in words, I have gone for this accessory several dozen times already. And then there’s this bug.

Please tell me, is it possible to do something about this and return the accessory?

You can make a bug report if corpse despawns even before rolls end, sure sounds like that's not how it's supposed to be.
And you can try to get that item by killing him again, there is no such thing as getting back items that have disappeared.