I'd check the following:
1) Is your traffic being blocked? You can connect with a supported browser with https, but maybe a local or network firewall is blocking the port. Worth checking out. Just make sure you're using a modern browser and that TLS 1.0+ is supported.
2) If you're trying to browse to the FQDN then I'd suggest pinging the FQDN just to make sure it resolves to the correct IP. If it's a different IP or isn't resolved by DNS, try connecting to the server with an IP address instead.
3) SSH to the server (port 26, not port 22). Run the command "show application status cpcm". Make sure that of the services running, that tomcat is one of them. If not, run "application stop cpcm" and then run "application start cpcm".
