Hello team, I have done over 1185 kills but the directive still states that I need 102 kills to Aurax that weapon. I have opened a support ticket and the team said it is a bug and asked me to post it here. Please take a look if possible. https://imgur.com/a/I7fSHPD
Duplicate of this bug report. P.S. Post on reddit about this. Probably game doesn't count vehicle kills.