Title – Impossible to change

Hi!
I try with “Force rewrite titles” and with “<title><?php wp_title(”); ?></title>” code in the header.php,

This is my wordpress multisite http://www.masfuerte.eu, I cant’ hide in the title “+Fuerte”, in admin setting don’t find anything,
maybe it found on database?

If I deactivate the plugin the title “+Fuerte” hide.
I use the last version of plugin.

Somebody can help me, please!

https://wordpress.org/plugins/wordpress-seo/