I downloaded the new coop maps as soon as they were available in late March and me and my buddy completed all of the coop missions and got the achievements for perfect coop...come to find later that my cousel shows the achievements, but they did not count towards my gamerscore and then I looked at my buddies achievements from my counsel by comparing games and his do not show up when I look at them but from his counsil it says that he has completed them and mine is exactly the same so basically I got the achievements but I didnt they will not show up on my gamerscore and I have tried everything that I can think of to get them back I have played through them again I even erased all the memory I had for GRAW2 and then played them again and still nothing please if anyone has any advice or solution to this problem it would be greatly appreciated

Try looking at this here: DLC achievement fix. You seem to have done this a bit later after it was fixed, but it's similar so perhaps worth a shot for you. Good luck!