Per your instructions:

 - I used Private Relay

- I cleared browsers.

I confirmed this is not an issue caused by stored cache and cookies.

Also, as I mention in my original post - this problem is happening in the APP for Windows and Mac. You don't list any instructions/recommendations on attempting to fix these platforms.

I reviewed and reconciled all of my OPEN PO's.  

As a test, I  deleted a PO, the corresponding Bill and Payment to see if the QTY ON PO would change to zero and it did not.  Then I re-entered the PO, entered the Bill, and paid the bill.  Now that product has doubled the QTY ON PO.   There is NO open purchase order.

My vendors require Purchase Orders.  Also, issuing Purchase Orders is a standard procedure, why would I bypass that and only enter a Bill?  

This problem is not happening on all Purchase Orders/Bills.  I don't know why the system is only doing this on some products.  

I confirmed the POs and Bills are linked and the PO says "Closed."