Posting purchase order aos batch printing previous po's

We turned on the print option print: “After” option on the Posting purchase order screen and set up a Form sorting for purchse orders. When we did this the posting purchase order batch that runs over night went from printing just the selected PO’s. To printing the previously posted PO’s as well.

ex. Day one 2 po’s entered, batch prints 2 po’s on day two
Day two 3 po’s entered. batch prints 5 po’s on day three. The two from day one and the other 3 from day two.

Has anyone else come across this issue?