Shopify holding payments for 120 days for verified transaction from known customer

Thank you for getting back to us. We have never had a charge back ever in our history. If our shop is classified as high risk, it is for reasons unknown to us and Shopify has not communicated with us about this classification. Unfortunately no one who works for Shopify has responded to us to clarify their policy or how to ensure we can avoid this in the future even if we do go through a third-party app. (We have read in the forum that other vendors had their third-party payment systems shut down and/or their store suspended because transactions were flagged as high risk, even though they were valid.)