As the server is hosted from home, sometime the droning of the Hard Drive and fans annoys me and as I only host this for fun and self learning it occasionally gets turned of. This meant it missed the Cron Jobs that that should have replaced the cert long before renewal date.
Added to that, when I moved I locked down the router config and only allowed port 443 thru to the webserver to only permit TLS/SSL traffic and not plain HTTP. In the main this has worked well, but also meant the certbot script failed to renew the cert on demand as it could not write to the .wellknown folder on port 80.
So, now port forwarded port 80 to the server and the certificate has updated as required.