I found what was wrong in my configuration.
Apache configuration in debian jessie restric the file system access to only 2 directories (/usr/share and /var/www).
# Sets the default security model of the Apache2 HTTPD server. It does
# not allow access to the root filesystem outside of /usr/share and /var/www.
# The former is used by web applications packaged in Debian,
# the latter may be used for local directories served by the web server. If
# your system is serving content from a sub-directory in /srv you must allow
# access here, or in any related virtual host.
<Directory />
Options FollowSymLinks
AllowOverride None
Require all denied
</Directory>
<Directory /usr/share>
AllowOverride None
Require all granted
</Directory>
<Directory /var/www/>
Options Indexes FollowSymLinks
AllowOverride None
Require all granted
</Directory>
So I had to add
<Directory /mnt/dati>
Options Indexes FollowSymLinks
AllowOverride None
Require all granted
</Directory>
and the virtual host started working fine without Satisfy Any
PS: the page with error was
Forbidden
You don't have permission to access / on this server.
Additionally, a 403 Forbidden error was encountered while trying to use an ErrorDocument to handle the request.
accessing the base url instead of url/index.php/settings/admin