It should be fixed. The issue is two-fold:
1. If you leave the round before the EoR Screen, it won’t unlock a weapon even if you unlocked it through progression in that round as the stats are synced during the EoR screen
2. If you don’t get an EoR screen (like the bug we had affecting a lot of folks), it won’t unlock until you hit the next rank AND get the EoR screen.
Now, looking through Slack on this specific issue, there’s a way to get the unlock without contacting EA Help (which, depending on your skill level, may be faster). You have to hit the next rank in the Class/Soldier progression AND get to that round’s EoR screen and any missed unlocks for that Class/Soldier Progression should pop.
TL;DR - EoR screen checks progress and grants unlocks. If you don’t get to the EoR screen or it doesn’t show up, it won’t give you the unlock until you do.