Getting error "Please Contact the Card Issuer"on iPhone Pro Max and won't connect to Apple Pay

Is your iPhone updated to latest iOS version? This message can usually be resolved by Signing out of your Apple ID and then signing back in. This will also remove any other payment method in your Wallet app.

Sign out of iCloud on your iPhone, iPad, Apple TV, or Mac - Apple Support

Here’s the issue we’re going to confront. Try to add the card too many times freezes the card from being added for a period time. The freeze is put in place as one means of reducing possible fraud. Some banks set the limit as low as 5 to 10 attempts.

How many attempts do you think you’ve made so far?

What on the phone is information about the iPhone. Changing cards rarely changes anything and I’d be surprised if anything changes. Here is what Apple shares from information on the iPhone.

• When you add a card to Apple Pay, card-related information, location, and information about device settings and use patterns may be sent to Apple to determine eligibility.

• Some of the above information, account-related information, and paired-device details may be shared with your card issuer or bank to determine eligibility and for anti-fraud purposes.

This emphasis I added. The information shared includes information about your Apple ID Account, iTunes Store usage, location (Location Services), address and other information. The banks use the information to determine their fraud risk from the device. Generally, the risk is rated Green, Yellow, Orange (not used by all banks) and Red. This information is shared with the issuing bank and the Token Service Provide (TSP). The TSP is usually the Payment Network Operator (MasterCard, Visa etc.). If something is amiss, the dynamic token is not sent to the iPhone from the TSP to the iPhone and the error message you see is sent. Did the bank explain that to you? Below is the data flow of provisioning a card for Apple Pay.

Apple can see if their servers are receiving the token from the bank. If no token is received is received, you get the bank error that you’re receiving.

OK, so the current error message is Can’t connect to Apple Pay. Please let me know when it changes.

You’re next step is Reset Network Settings.

>>Reset your network settings

If you're using iOS or iPadOS 15 or later, tap Settings > General > Transfer or Reset [Device] > Reset > Reset Network Settings.

If you're using iOS or iPadOS 14 or earlier, tap Settings > General > Reset > Reset Network Settings.

This also resets Wi-Fi networks and passwords, cellular settings, and VPN and APN settings that you've used before.<<

If your iPhone or iPad won't connect to a Wi-Fi network - Apple Support

What country are you in? What country is the bank in?

Have you contacted your card issuer? If so, what did they say?

What country are you in? Do you use a VPN?

Is there anything else you’ve done, just so I don’t repeat the same things you’ve already tried?