I have the same problem, and it happens whether my cookies are cleared or not, and behaves the same on Chrome, Firefox and Edge.

In the PO, the fields visible are # (sequence), Product/Service, SKU, Description, Amount, Class, Received, and Closed.  Each line in Received is 0.

I even include the Rate and Quantity in the import, and NOT the Total Amount.

Is there somewhere to customize the PO?  It certainly has no value as a PO if there's no quantity included.