Set not redeemable

I just grinded to get all the 96 ovr ultimate legends players and the 96 ovr cb Andre Johnson card so that I can redeem them for the 99 ovr ultimate legends Andre Johnson card in mut , but it will only allow me to add one of the cards to the set and won’t allow me to redeem any of the other cards that I have in my items. How am I able to redeem this set?