I am running LetsEncrypt through the Plesk control panel. I can assign SSL's using LetsEncrypt absolutely fine, but when it comes to automatically renew the certificate it cannot automatically renew the www subdomain. I am 100% sure that this is enabled when I first assign the certificate.
Because of this, I have to manually renew the certificate and re-check the "Include the "www" subdomain" option. It renews the SSL certificate fine, including the www subdomain.
However, because of this it brings my clients websites down.