Among other progression bugs being reported, this one is affecting me, but seemingly not many folks. You need to claim a primary weapon from a Mystery Box and get kills with it. But the game never registers claiming a weapon or item from the Mystery Box, for some reason. I've probably rolled 15 or so weapons so far, across separate matches and operators. It never recognizes that a weapon was purchased from a Mystery Box. It worked fine for a friend when we were playing yesterday, though. : /

Any ideas? Otherwise this is just a general bug /u/TreyarchCM might hopefully take note of.

Edit/Update - 2023/12/07:

First Mystery Box I opened today finally recognized the gun purchase and credited my kills. Finally past this stage.