Unable to update Need by date or qty on Open BPA Release shipment.

Hi Friends,

User is not able to update Need by Date or Promise date or Quantity in Open PO Release shipment form

Security Level: Public

Access Level : Full in document types for BPA Release

There is No Holds or Freeze.

when we try to remove existing need by date or promise ... its not allowing us. There is NO error or not allowing to change/update

There is no form personalization or customization.

Qty field also not allowing to update and its not grayed out.

There is NO relation with OSP Job(s).

Partially received/billed. however i am able to do changes in Test instance for same Release.