Did you select the original invoice from the Adjusted Doc. field? Or, if you entered a credit note within an invoice batch, did you select the original document to be credited from the Original Invoice field?

Doing either of these will match the credit to the proper document. They won't show on the Aged Overdue Payables report and will be cleared to history when period end is run.

If you didn't match the credit entry, you'll need to make another entry to reverse the original adjustment and match this entry up with it. Then do another entry to credit the original invoice document.