PO Missing when Creating new Proforma

When you want to create a PI and the PO you want to select is not in the list, as in the below screen:

You can do the following 

Check if the PO is in already assign to PI

>Navigate to the Proforma Invoice List page

>Search for PO number as in the screen below

>If the PI pulls up the go into the PI detail page and remove the PO to re-allocate it to the new PI you want to create

Remove the PO from the PI or you can keep it if you want it to remain on the selected PI

NB - Ensure that you search with the correct PO. If you can't find it, please log a tickets