RM with negative amount, doesn't take the due and discount date.

Hello,

We notice that for all the RM's the due and discount date is the same than invoice date, even using a payment term.

but for RI's its works okay.

We have a payment term with dates 60 days from invoice date, when we checked RI's are ok. but no RM's and seems that happend with every single payment term that is used in RM's invoices.

Do you know what this is happend?

Many thanks in advance