When a PO is activated, the estimated price in a line item is encumbered. It is possible to change this price after activation.
Retrieve the Purchase order
Note the PO and Line Item Estimated and Encumbered Amounts Before Price Change
Change the estimated price in the line item and reload the page.
You will see the total Estimated and Encumbered amounts for the PO the line item change.
If you check the Debit tab in your fund you will see the entry for that line item listed first with the updated Encumbrance amount. The Origin Amount remains the original price. The Debit Time remains the same.