specialization code assigned to other cosole?

ok so today i checked me and my sons email and found the codes weve been waiting for redeemed them and thought that was that when i went to the xbox active downloads it says assigned to other console checked my sons and the same thing i know for a fact i didnt mix up the emails and gamertags i checked his email first and redeemed his code using his microsoft account signed out and did the same with mine how did this happen and how do i fix it bought 2 le halo 4s and a console son had an elite and i swapped him to my halo reach console set up my halo 4 console and transferred licenses on both consoles before ever playing the game why has this happened