By default, WordPress prefixes private or protected pages with the corresponding keyword (blocking non-registered users from viewing them).
Simply add the following code in your functions.php
to get rid of the prefix:
function remove_title_prefix($format) {
return '%s';
}
add_filter('private_title_format', 'remove_title_prefix');
add_filter('protected_title_format', 'remove_title_prefix');