When does the Billing Summary Pop-up Alert occur

When does the Billing Summary Pop-up Alert occur?

The Billing Summary Pop-up Alert occurs when you try to Auto-Calculate Billable Service after it has already been determined.

The message is alerting the user that the billable service has already been determined on either 'All' the rows or on the selected rows in that page, so there is nothing to review or change with the billable services,