When a site user attempts to pay for an order using an integrated payment method, show the return error from the payment service on the details for the order. For example, a few years ago, we would show the message from Authorize.net for a failed transaction on the status history of the order. This was useful, as support did not have to ask programming to dive into the logs to get the actual Response Code from Authorize.net to confirm to the client why a transaction had failed.
If i'm correct, this is functionality that was actually removed. Now we have to investigate why things are happening. Please add it back.