Apple Pay Issue

If the Apple Pay Issue Detected message appears, you won't be able to use Apple Pay or Wallet for payments or access until you reinstall iOS or iPadOS on your device. Some Wallet passes might still be available while payments are unavailable. If appears if there a software problem with your iOS version, and you will need to reinstall it.

click here ➜ If you see a Cellular, Ultra Wideband, or Apple Pay Issue message after an iOS update or restart - Apple Support