Gilded RAAM Challenge - Complete Co op campaign on hardcore. Not working

Yesterday I finally finished the cooperative campaign in hardcore difficulty, I had already completed the two previous returns, but at the end of the co op campaign did not give me the third achievement to unlock Gilded Ramm, how can I solve this error?
Thank you
gt Sscorpionz

5 posts were merged into an existing topic: RAAM Challenge Not Unlocking