Personally, I’d try logging-in through the native IP address of the device (https://10.10.0.2:9443/admin in the example from your link).
Also, does your server.properties contain a line that says allowed.administrator.ips=0.0.0.0/0 ?
You’ll need to add a sudo to the front of that command to see details of processes that you don’t own…
sudo netstat -plnt
Also, it might be worth taking a look at this:
Pete.