Cash App monitors your account for anything that looks out of the ordinary. If a potentially fraudulent payment occurs, we cancel it to prevent you from being charged.

When this happens, your funds will instantly be returned to your Cash App balance or linked bank account. If not, they should be available within 1–3 business days, depending on your bank.

To reduce the risk of payment beings canceled:

Only link debit or credit cards that are in your name
Only send payments to or receive payments from people you know or reputable businesses
Confirm the recipient’s phone number or $Cashtag before sending a payment
Frequently use your Cash App to build up a healthy transaction history

Hope this gives some insights.