Customer Partial payment

Hello,

I have the following scenario:

a customer makes a payment for an invoice that is a great deal less than the full invoice value, the underpayment was post as partial payment, but the original invoice be shown as paid and only the difference remains open.. As Residual payment functionality, but the difference is: for the partial item, we dont have the reference from the original invoice, neither BSEG/BSID-REBZT = Z.

In FI-A/R I know that for partial payment: the original invoice and payment document still open. And for Residual payment: Both, original invoice and payment document are cleared and only the residual item remains open.

Any idea why partial payment is working similar as Residual payment?

this may have to do with the FSCM module? (The company has FSCM activated) I know A/R but I dont know FSCM functionality.

thanks!!

Anna