I am configuring a results box for only a portion of my SharePoint 2013 site. Initially I came across the problem that the results box would display results even before any searches were executed. I've fixed that, but now the results box is displaying Nothing here matches your search even before a user searches for anything. Is there a way to disable this or change to a different text? My users will be confused if they see that message without even searching for anything.
I think that this might push you in the right direction. Please find below links and let me know if this fixes issue.
Not sure if you were using a web part but here's another one that might help with the issue.