Hi,
If your website is browsed by Safari, this error message appears in the console:
Failed to load resource: too many HTTP redirects
And after this error message appears, the zoomEffect starts working. I strongly believe this problem is related to .htaccess file. Are you using the official htaccess file that comes with Joomla by default? Do you have a custom redirection rule in that file (some like, redirecting non-www to www or something like this...)?
If you have, try to comment out those custom redirection rules for testing. Then, test again on Safari browser. Open the console and check if you stop seeing the "Failed to load resource: too many HTTP redirects" error message at the end.
Regards.