Used a gift card, have money left, but can’t buy a kit.

Hi, the title is pretty self-explanatory, but I don’t understand why it’s not working. When I try to make a purchase in the game, it says I have 5 euros in my wallet, but when I check my account, there’s nothing. It’s strange because I used the same gift card to pay for my game extension without any issues. It also seems to work fine when I use my card, but not when I try to pay with my EA Wallet.

It would be a lifesaver if someone could explain I'm really confused :(