Purchased players disappear or change to concept players

I have had a recurring problem with player disappearing from ultimate team. Those in my active squad change to concept players. This has been for untradeable cards and tradeable cards. Some were received in promo packs, some from

purchased promo packs. Some players purchased in transfer market. It has happened for three days now.

I spoke to EA help twice. First time they compensated with coins as felt my account had been hacked. But after a change of log in details, within 5 minutes of closing the game, the same happened again. EA help told me to write in here and that they felt it was a game bug and an issue for the Game Studio.