Fallen from grace error

Cant complete this quest, cleared it 2 times and nothing happens

Are you sure that you have reached 0 monsters remaining?

Type "/remaining" in chat to see how many monsters are alive in the zone.

happening to me too. says 1 remaining but it's nowhere to be found. unless you count the expedition NPC.

Can be a ghost sometimes, this happens in Act 6 when clearing the Strand.

i know, this is an old post, but for the first time, i got the same issue oO running in snake-like lines all over the map - no spawn or enemy in sight.. missing exactly 1. i did use the crucible league mech though in this map. no clue if its related

Edit: resetting the zone and clearing it again worked ...