Search results only show in Safari (not in Chrome/IE/Firefox)

Troubleshooting a custom search instance

The search page works fine in Safari, no problems.

But on other browsers (Chrome, IE, Firefox) the results are not showing up, not even the busy bar or error or anything.

If I look at the page source html, the results are there but they are not displaying on the actual page.

Any help is much appreciated

https://wordpress.org/plugins/ultimate-wp-query-search-filter/