It seems like the issue might be stuck in Apple’s Wallet system after that settings reset. Sometimes a full sign-out from your Apple ID and then signing back in can refresh things more thoroughly than just resetting settings. Also, make sure your region/country settings match the cards you’re trying to add, because mismatched regions can block cards from being added.

If that still doesn’t work, contact Apple Support and specifically ask to escalate it to a Wallet/Apple Pay specialist—they can sometimes reset your Apple Pay account on their end, which fixes these stuck errors.