#1 order top actor in feature fim lost postion due to glitch - how to fix

Our lead actor has been displayed as the first/top Star on our feature film title for many months. We initially labeled him in the order as #1 when listing the new title and never intended this to change since he is top (#1) in the film's credits. Yesterday, I added one minor cast credit, and immediately afterward our #1 top lead dropped from the first position and is now appearing lower, according to STARmeter/popularity.

How do I restore him to the top position? When I click to edit the cast, the ability to update/restore the order does not appear. I'd also like to know how to prevent this from happening again since he was supposed to be locked at #1 indefinitely.