Are you adding the card from the 'Previous Cards' section or do they show up in that section?Still can't add any debt or credits cards to my Apple Wallet. Done every fix for it and have called both Apple and my banks. And the banks even ran some tests on my debt cards and have said that once it pings off their servers and goes back to Apple on my phone it then get declined. BUT for some reason my Apple watch running Watch 11 adds the cards with no problems. my iPhone is a 15 Pro.
If so, delete the cards in there, give it a minute and try adding the card again as new.