Communicate with WordPress.org or SecuPress.me
Your site must be able to communicate with WordPress.org in order to receive security updates, major updates, plugin updates, and themes updates.
It must also be able to communicate with SecuPress.me in order to receive updates from our plugin.
Also, it must be able to communicate with all the sites that offer premium plugins installed on your site.
SecuPress can only verify if this is possible, but it is impossible to know why your site would not be able to communicate with external sites.
First, you need to contact your host to tell them to authorized wordpress.org and secupress.me
If the problem persists, contact support by giving us FTP access, we will do tests on your installation.