Just today, I have finished one challenge wherein you need to kill enemies with a weapon, (10 enemies with the Sidekick) and started another, (15 enemies with the Commando) and with both challenges, the game wasn’t counting every kill I got with these weapons, which dragged the Sidekick challenge out for a couple games longer than it should have, and I suspect it will with the Commando challenge as well. Please look into this. Thanks.
You must land the kill with the weapon.
If say you last shot someone with the Sidekick but they died to their own grenade or fell off a cliff or exploded by a vehicle, the kill may credit to you with the Sidekick but it doesn’t count for the challenge.
The problem is, I know I am, because I stole my friend’s kill by landing a headshot on an unshielded Spartan with the Commando. Didn’t count. It gave me the points for the kill, but didn’t count it in my challenge. Same for a few Sidekick kills. One of my Sidekick kills that wasn’t counted was even a Perfect