Challenge for kills or assists with battle pickup from stash in br not counting

Trying to complete the above challenge.  I have gone to the stash to pickup a weapon and have gotten a minimum of 3 kills with it in BR and none have counted towards my goal of 5 kills or assists with battle pickup from stash.  Still sitting at 0/5.

I had the engineer open the area, but I open the box and take the weapon for use.  Do i need to be the engineer?