Spartan Officer achievment glitch?

So I just ranked up to lieutenant in Halo 3 today and I did not get the Spartan Officer achievment. Anybody know whats wrong? The spartan officer symbol is in my service record but I don’t have the achievement or the rogue helmet.

I’ve seen this happen a long time ago, you may have to reach the rank in another playlist too.

Get to 50 EXP in a playlist. I had this pop a week ago on another account when I hit 50 EXP in Lone Wolves