"Fraud Suspected" message pops up in Apple Pay

My son is in the Marines so we set up apple cash/apple pay so i can send him money when he needs it. Sunday he sent me a request to send him money and every time i tried a message would pop up "Fraud Suspected" and i would hit send anyway and it would not allow me to. This is very frustrating to me. I called my bank and it was not an issue with my debit card. Can you please advise

Roxanne

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