When you do the rescrape wizard and click update only update empty fields it will update all the fields for tbhe actors for all the episodes even if you manually have edited the nfo it will still update the nfo using the actor source you selected. For example if you scrape an episode and manually change the actors that were scraped iin the nfo and then use update wizard if you add the imdbid to a differnt episode and then use the rescrape wizard it will overwrite what you manually chagned and replace it with the actual actors from the scraped source it will not update the ones that are only empty actors for the episodes it will scrape all of them.
Sorry not sure if makes sense or not.
Sorry I accidentally posted it in the discussions instead of tickets
In short it will update the actor fields even if they aren't empty in the nfo or on media companion when the update empty fields should only update the episodes that have no actors in the episode.
Whenn i say no actors i mean no actors in the nfo/Media Companion not from the website it scapes from
Fix in place for the next release.