Is vendor name a field coming from the item record I assume? Scroll to the bottom in the UI and try ‘item fields...’. That will join to the item record and get available fields there

It is coming from the item record. But if you do a join on the item record and pick item code (which is the correct field) you will get back the results for all vendors’ item codes associated with that item, not necessarily the one you see on the PO.

Add it to the criteria as well? Item fields...vendor?