You are up against Banking regulations that has nothing to do with Apple as they are not a bank. It makes no difference what device you use or any other Cash App, you will still be under the same scrutiny. It takes little effort to find the same thing happen to users of Cash App, Venmo, and Zelle by a simple web search.
The banking regulations that apply are the Banks Secrecy Act and the US Patriots Act, both of which were passed by Congress and all bank must follow. Even the banks have no leeway and their hands are tied. The specific rules require them to follow the KYC (Know Your Customer) laws for verification and report any activity that may be seen as suspicious. This could be from a transaction you have made or a person made with you where they are being investigated. Banks are even required by law to not disclose to you if you are being investigated and surely cannot tell you the reason why.
Anyway, it makes no difference to us what device you choose in the future and would strongly recommend to get anyone that best meets your needs.