Error code

I ran Autotune on your site and received the following error:

Test: Facebook Javascript library inclusion
Fail: Another Facebook extension is installed, including the Facebook Javascript library, and may conflict.

This error means that another extension, plugin or template on your site is including Facebook's deprecated all.js Javascript library. That is the 'old' version of the Facebook Javascript API which was discontinued. It's no longer meant to be used and can cause conflicts with some JFBConnect features, as JFBConnect uses the recommended sdk.js library. Some common extensions that included Facebook features are JomSocial, EasySocial, K2. You will need to check your plugins, components and/or template for any Facebook features and try to disable them.

-Melissa

Additionally, I see you're running Joomla 3.8. Can you make sure to enable the "Disable SSL Validation" setting in the JFBConnect backend > Configuration > General area? There is a known issue with JFBConnect / Joomla 3.8 for authenticating with several of the social networks that will be fixed in the next release. This setting will let you workaround the issue for now.