Hello i get the Achievment Size is Everything today.
Then I have download my Gamertag on my Xbox and the Achievment was not there 
So I have played the Crimson DLC and get 24 Kills with the Machine Gun Torret and the Achievment donāt pop out.
Need helpā¦
Thank you
PUSH
Ouchā¦ sounds like you need to clear your cache so that you can unlock the -Yoink!- achievement again.
Why did you download your profile? It sounds like you didnāt give it enough time for the achievement to back itself up at Microsoft which is why you lost it when you downloaded your profile.
Iāve seen several people post on here with the same problem, but no word from any 343 employee about it yet.
I posted something in the stickied āissues being investigatedā thread, but again, no word from an employee yet.
I hope it fixes itself for you.
I imagine it has more to do with this so-called ātrialā of the DLC. If you were participating in the ātrialā then I imagine the achievements were removed since you had not purchased the content, which probably had something to do with the recent patch. The same things happen when you beta test something - I had been a beta tester for both Dragonborn and Dawnguard DLCs for Skyrim and none of the achievements earned during the beta period would show up on Xbox.com, only my console. Then after the beta was over, I had to download the DLC again as well as recover my gamertag, at which time all the achievements earned were wiped and had to be earned again.
So if you were using the DLC as a ātrialā, this may be what happened. If you had actually purchased it, then there is a problem.