Why is the card being declined for "Suspected Fraud"?

A card might be declined for suspected fraud due to Visa fraud monitoring rules,
Visa assigns fraud scores to each activity.
Unfortunately, we don't have visibility into the specific fraud monitoring scoring categories that Visa uses, and they are not willing to share that information with us. It's important to note that not every decline due to suspected fraud will result in communication from Visa. However, if a customer reaches out to Visa to authenticate a declined transaction, Visa will suppress the "suspected fraud" declines for a short period of time.

Please review this in our guide to learn more about visa fraud monitoring. https://guides.unit.co/cards/card-fraud-monitoring#visa-transaction-scoring