Hi,
I’ve run a few tests, and it appears to me that the theme might have an override as well, or some sort of issue with printing the results, I’m not sure yet. If I turn on the live resutls, it returns them as expected, but on override there is always only the first result there.
Unfortunately I’m not able to tell, it might be a theme related issue as well. If you want, I can take a look, but I will need temporary FTP access for that. I will try to look through the plugin as well as the theme’s search results template file to check where the results are lost.