@DavidNovak -- Are you seeing a white screen or an error screen when the story doesn't load?
There is a known issue we are working on addressing where if you are logged in and view a publicly shared story, and then log out and try to access the story anonymously the story will redirect to an error page for a period of time after you've logged out (until your local cache expires, about an hour).
This issue only affects the one machine where the story was viewed while logged in. Others are still able to see the story as expected. If you try to view the story in a new private browsing window (or clear your browsing data) the story would be viewable.
Does this sound like the issue your customer is experiencing?
Owen Evans
Lead Product Engineer | StoryMaps