Intercompany customer not recognizing correct terms

We have intercompany customers not getting the correct baseline dates and selecting the correct payment terms. This does not happen on invoices on customers; but does on credit memos with customers. We have looked at the User exits and I don't see anything in configuration for this.

Example:

intercompany customer A has payments due 20th of month following invoice.

invoices processed select the correct date and set up to pay the 20th of the following month. post date 5/1, pay 6/20

credit memos processed select the current posting date and set up the credit to be taken immediately. post date 5/1; pay 5/1

The customer master IS marked with the same payment terms on both invoices and credit memos.

The Vendor on the other side of the intercompany is working correctly.

is this a setting somewhere in config that I am missing? or what could be causing this?

Suggestions are appreciated!

Thanks