Arbiter of Ash Bug

Ran arbiter of ash 3 seperate times with a friend, first 2 times we beat the boss but he didnt drop the book of knowledge thats supposed to drop, the 3rd time we died 1 time and attempted to respawn with the 5 revives it gives you but it instead removed us from the map and destroyed the portals.

we essentially have lost out on 3 books and other loot due to these 2 bugs.

before I died the 3rd time boss was really low of health & thought he was already dead, so when i resurrected to give another try, for some reason he just disappeared, and the book of knowledge dropped with no items or whatsoever. I can't even interact with the 'object that fell'