Problem with Halo ODST achievements?

[oddjob428]

My brother and I just completed Halo ODST co-op campaign but didn't get our achievements at the end. I checked and found that we didn't get credit for 4 of the levels. I estimate we were shorted 420 achievement points since we were playing on Legendary difficulty. Has anyone else experienced this problem?

[Unreal]

No I never experienced it myself. But I have been told that playing the game in co-op might be the reason for the glitch. It sucks if you have to play again through on Legendary but it is a fun game.

[wicked_d365]

My brother had the same problem. Finished a co-op legendary run and didn't get the achievements, but it worked fine for me. Sucks to hear.

[oddjob428]

I played the four levels again I needed and got my achievement points. You can play them over in either single or co-op and it still gives you credit towards the end achievements.