Bugged Affinity quest, "Gather Floating Spirit's Souls"

[backstreet4]

There's this quest given by Master Vim in the Fel Lands, in which I need to gather 80 empty souls from the floating spirit mob. After around 300 of them killed, not a single one dropped. Tried changing location all around the Fel Lands, tried changing server, tried changing realm multiple times, nothing seems to work. What's there to do?