Google Maps not showing in Firefox

Hi, I embeded a Google Map via the shortcode from the Plugin “Symple Shortcodes”. The Map renders fine in Chrome and Safari (have not tested IE). In Firefox the Map does not show, even though the Google Maps code is showing up on the page (you can check it out with the inspector). Why is Firefox not rendering the Map? This is the case across various machines.

You can check it out here, very bottom of homepage: https://www.catagonia.com/wp

Thanks in advance.