Currently if multiple invoices go out in an ACH payment - the vendor is only receiving one invoice detail in the e-mail and does not know how to apply the multiple invoices within the payment. All of the invoices should be included in the e-mail that make up the payment amount. It's confusing and frustrating to the vendors.
This was also an issue in Legacy Datfaction. We decided to change the max invoice per payment to 1 for specific vendors.