attachment not unlocking

During a match, and leveling up any weapon, it notifies me I have unlocked a certain attachment Example: vertical grip, then trying to use it, the lock symbol is still there, so I cannot attach it, but I have passed that certain level to get it, by completely shutting the Game down and restarting it , only then the lock symbol disappears and I can Attach it... This is on the Xbox console version, but I see on the Forums, PC is also having a similar issue.