Twice in the past couple days, while taking group BP, the mission stops counting enemy kills. The mission remained active, and had to be aborted/restarted to work again.

Bump. This has happened again a couple times. I've actually had two BP missions active whan another group member tried to abort/retake the mission.

I think the way it works now is each member of the group has to take the mission in order for their kills to count. Don't know if this was intended or not.