Gap between Due Date and Payment Terms

Summary:

Hi.

Somehow in one of our Business Units, we have 50% of the AP Invoices with Due Date been calculated based on "Invoice Creation Date + Payment Terms" and other 50% of the Invoices with their Due Date been calculated based on "Invoice Date + Payment Terms".

For all Business Units we've configured that Due Date will be calculated based on Invoice Date and not Creation Date.

Is there anything that can override it? We want to make sure that system will always consider the Invoice Date for Due Date Calculations.

What reason there is that the system won't consider Invoice Date, and take System Date intead altough the setup is pointing on Invoice Date?