Unlockable extended mag bug (AC-42 and VCAR)

Same for me this is a big issue for me because I am currently trying to get tier 1 on the AC-42, iv unlocked everything and I’m currently using the extended mag that’s supposed to give you 50 but instead is 39. I thought it was the only weapon with that issue but clearly there’s another one, this needs to be fixed as soon as possible. You put so much hours grinding to unlock all these upgrades and it still doesn’t give you the full benefit. Please fix.