There are 3 options:
1. You didn't save him (maybe your memory is just wrong).
2. You saved him but you fast clicked next pack, and player hadn't saved yet (player is stored when you see ,,stored" sign instead ,,store players in club" or ,,send in club"). If you clicked next pack before you saw that ,,stored" sign, player probably didn't store in club.
3. It's a bug of game, but it's the least likely option