When an update happens to a purchase order that is already confirmed the PO changes from confirmed to Approved/unconfirmed, this happens for a series of events that are in the logic of the IsChangeConfirmationRequired logic. This list a series of events that make this confirmation to change, but this list does not include the sales tax recalculation logic. The request is to include this logic as this is a major change on the PO, it actually updates the tax charges of the PO, therefore is important to unconfirm to allow users to check again the calculation to avoid impacts of new taxes on the PO to be paid. This is what we believe should be changed because it affects totals on the PO, similar to when you change a unit price.