Thanks for your reply,

but this is not a filter problem, as I use the standard profit and loss report and I don't use a filter for this report

also, if you check the instructions I had linked, we first create an invoice for $80 (as example), posting to the expense account Charity/Donations. The balance now is $80.

But then we create the credit note for the same amount with the same line items which also posts against the same Charity/Donations account, thus, making the account 0.