There is a bug that stops the Halo 4 stats website from registering the Crimson achievements. I have 52 out of 57 achievements and the website says 48/57 which is clearly wrong.
I expected it to be fixed now but clearly no one has brought it to anyone’s attention. Mods please can you inform someone so it starts updating properly.
I have the same exact thing going on and I’ve completed it all on my xbox.
I posted this 11 days ago in the ‘Waypoint’ forum (as it’s more of an issue with the Waypoint site/app than a topic of discussion in the Halo 4 forum):
Crimson Achievements not recognised
However, that forum seems pretty slow. That was 11 days ago and it never got a reply.
I’ve just taken a look now and there’s a couple of similar topics been posted since then so I’m pretty sure they know about it as they check that forum often (the 343 Admin account is pretty active there). However, they don’t seem to have said anything about this issue yet…