Regardless of autologin, I'm also having a problem on your site of being able to log back in again after creating my account and logging out. This is probably the cause and needs to be sorted out.
I do see an error on the console that should be resolved before we continue:
k2.frontend.js?v2.7.1&sitepath=/:9 Uncaught ReferenceError: jQuery is not defined
at k2.frontend.js?v2.7.1&sitepath=/:9
(anonymous) @ k2.frontend.js?v2.7.1&sitepath=/:9
Please try switching on the JFBConnect > Configuration > 'Load jQuery/Bootstrap' option to see if that helps.
-Melissa