@lubos please enable displaying the purchase invoice reference number for Debit Notes
just like Credit Notes
display the sales invoice reference number when selected by the user.
What screen are you referring to?
when you select an invoice the credit note applies to, it is displayed on the final credit note.
similarly, for debit notes the purchase invoice number is not displayed even if you select it on the entry form.
Fixed in the latest version (20.6.26)
i can confirm this is fixed now.