Bug with quest "The Way Forward"

Hi,

my ranger character Sejuna is stuck in the quest "The Way Forward" in the step "Kill the Black Guards" (Captain Arteri) as the Thaumetic Emblem doesn't drop.
I killed him several times on different days, but still the Emblem does not drop.

Difficulty: Cruel

Is there a way i can make him drop the emlbem in order to fulfill the quest (and earn my reward)?

thanks,
Nordstern

I used Puncture as well.
Good news: Patch 1.0.0 c solves the issue.

Nordstern