Action code set Update for Root even when no changes are done to it in Modify Order

Hi,

When we create a modify order with addition of child product on an existing asset, the root asset is also getting action code as Update.

Since there are no changes done to the root product, the action code is expected to remain as -.

Apart from fields mentioned in Delta Line Item Compare Field n User Property of Business Service SIS OM PMT Service, Is there anything else referred to identify the change to mark the action appropriately?

I have compared all the fields in the user property both on Asset and Order Item and there is no difference.