Suddenly getting pin request for Credit Card

How can I get help from Apple Pay support. My credit card stopped working with Apple Pay after about a month. I'm being prompted for a PIN, but there is none. I've confirmed with issuing bank the card does not have a PIN. I've deleted and re-setup the card with same results. The same result has happened at multiple different locations. It seems Apple Pay is treating as a check card, but I've made sure it's explicitly setup as a credit card. Given it worked, but started prompting for a PIN-it seems something has changed within the Apple Pay system.