I created a group and a site for this group.
Then I created a user belonging to this site adding it to the group and editing the user profile putting the right site membership.
Then i created some pages for the group website, and for each page I set the permissions to view only for "Siste Member" Role.
The result is that the pages are not available for the usre (error 404).
The pages result available if i add the view option for "User" regular role.