What counts as stationary weapons for the support proficiency 3 assigment

Tindahbox

This might be posted before.
I was wondering what counts as the 'kill 5 enemies with stationary weapons' for the 3rd proficiency assignment for support.
so far the stationary lmg, the AT gun and the AA gun don't count as those kills.
I know this is a beta and i'm sure there are several things not working or bugged but i just wanted to figure this out

RoddersaurusRex

I think you're using the right weapons... could be a bug?