Legion Encounter Boss in Twilight Temple unique map doesn't die

Bug # 863021954

https://imgur.com/VOXMQpE

Legion encounter spawned in my Twilight Temple map.

I triggered the first Cold Orb encounter but didn't complete it, instead went to clear the rest of the map. Legion encounter was on Fire side of the map, and spawned a Boss mob. When Boss HP reached 0, nothing happened.

I then finished up the map, completing first the Cold Orb encounter I left behind, then the other Orb encounters, then the map boss. When I go back to the Legion, boss is still there in an undying state :D

Build is a Scourge Arrow Poison Pathfinder.

Had this bug several times now, most of the time its Hyrris that wont "die" and leave loot. she just stands still.