Released Amount in Contract Purchase Agreement does not show correct balance

Summary: In the Redwood purchase agreement pages, we can see the fields 'Released Amount', 'Received Amount', 'Invoiced Amount' and the 'Purchase Orders' link. However the definition of 'Released Amount' is unclear. What really counts towards the calculation of 'Released Amount'?

For e.g., If CPA is for $100, i create PO for $80. Th CPA released amount shows $80. Now if i receive the order and invoice for $70. I finally close the PO, expecting no further receipt. Does the released amount update from $80 to $70, indicating the correct balance left on the CPA?

What happens if the original PO was cancelled after it was approved. Will the released amount get updated to reflect the correct balance left on the CPA?