The plugin that posts status from JomSocial to Facebook is the jfbcjsactivity plugin. Make sure that's published in the 'community' plugin group and check the settings in there.
Then, make sure the status being posted is set to 'public' in JomSocial. We will only push public posts to Facebook. If that doesn't help, let me know your JomSocial, JFBConnect, and Joomla version so we can investigate more.
Thanks,
Alex