Change in AP Invoice Header and Lines the status of approval field changes to Require RE-Approval bu

Hi All,

We have a requirement where whenever there is a change in header and lines and distributions , then system should ask for a require- reapproval that means it should call Invoice Approval Workflow.

When we changed the header value and save the form , the approval field value changes to require re-approval from Approved.

and the same is happening when we change the details of the line.

But when ever you change the distribution details or add any new distribution details, the status is not changing to require reapproval but simply accepts the changes made.

Can you please help us know how to achieve this functionality to control the changes of the distribution and whenever there is a change made to the distributions , the status should change to Require Re-approval.