Can't complete Silent Crusade Quest

Describe the problem. Be as specific as possible!:

My Aran has completed all of his Silent Crusade quests, but when I tried to do the first quest on my Cannoneer, it never registered the killings of Black Wing Henchmen.

 Images of problem

Try doing it without a party.

Try doing it without a party.

Okay, NOW it works. But why won't it work when I'm in a party?

Okay, NOW it works. But why won't it work when I'm in a party?

Dunno. Just a thing with Silent Crusade. :/