SEO Yoast and WP MU, plugin's settings access

I'm using SEO by Yoast plugin (v371) with WP MU install (v461) and, even with admin and the super-admin login, i do not have access to all the settings of the plugin, i only see the plugin's dashboard, search console and the invite to sign up for the premium version (lol).
Someone can maybe advise me how to gain the full access for this plugin's settings in ?
Thanks a lot,