User Group privacy not working with WP 4.0

When i set in a single page or post the “Access area” restricted only to a group of users that i’ve created, it doesn’t work. If i access to that page from another pc without logging in to the website, i can visualize all the content.
With the previous version of WP (3.9.2) it works…

https://wordpress.org/plugins/user-access-manager/