Location Change on PO Not Updating In Item Availability

I have a PO entered for an item with a primary location of blank.  We are changing the primary location to a non-blank value using P41021 row exit to Change Primary.  There is a quantity "On Receipt" fir this item, so I am unable to perform that task.  I have used P4310 to change the location on the PO to the secondary location that I want to be my new primary.  The Item Availability still shows the "On Receipt" quantity against the blank location.  How can I change the On Receipt location on the PO?

Thanks,

Jeff

EOne 9.2   TR 9.2.0