If there are no matches to my search, why does reults count say 8?

I am setting up a search page for a site collection on a farm running SharePoint 2013 Enterprise Edition.

I have set up the search refiners and the query rules for the results webpart, set up the relevant managed properties for the refiners, entered some sample data into the list and run a full crawl. When I enter a search term I get all the expected refiners and the results counter displays the expected number of results but the actual results don't display. Instead I get the 'Nothing here matches your search' message.

I'm completely lost. clearly the search crawler has found and indexed the results it just refuses to display them.