The Cash app keeps a strict look at the payments done by the customers. If a server detects an unusual transaction from any account then it automatically cancels it to protect the account from hackers attack. If you are getting a cash app payment failed error then it might be possible that the cash app server has itself taken this action to protect your account from fraud. https://www.phonesupportnumbers.net/blog/fix-my-cash-app-failed-for-my-protection/