@mathiaso. Thanks for responding. As I explained, the javascript filter works by filtering an exact phrase. I renamed some of the files at the demo site to have spaces instead of underscores. I have confirmed that it works as expected.
If you are still experiencing a problem with your site, I invite you to please post the link to your site’s listing page so that I can see it in action. The listing filters an exact word or phrase.
Hope this helps.