Hey Alessandro,
We need to test deactivating third-party plugins in your site but since it’s live, doing that could disrupt the operation in your live site. Is that OK?
If not, please copy your live site to a staging server and give us Staging WP Admin and FTP access instead.
Also, is @gmeynaud your other account? I asked because you posted login credentials in the original poster’s thread and the secure note can be seen by the original poster or thread owner. If that is ok, we can continue on this thread.
If that’s not ok, please create your own thread and update your live site’s username and password. Since you already started a discussion here, just post a link to this thread for reference.
Thanks.