If you’ve been having problems with your American Express cards and Apple Pay in iOS 16, you’re not alone. Apple has acknowledged an issue in the release notes for iOS 16 beta 6 where “American Express cards might need to be removed and re-added to Wallet.”
Amex and Apple Pay bug in iOS 16
The issue is affecting many people running the iOS 16 beta 6, including myself and multiple other 9to5Mac staffers. Essentially, the problem is that your American Express cards will be randomly removed from Apple Pay without reason, and you have to manually re-add them to your device.