Hi coppit,
I'm having the same issue as apefray - I've had noip docker running for a month, it showed the same message. 3 weeks in I got an email from noip saying I had to manually renew as I was coming up to the end of the month!
I'm not a networking guru but I've noticed something with my openvpn, which is installed and working, and I noticed for some reason it connects through the bond0 and not eth0 interface. Perhaps this is the issue here? Is there a way to specify a variable in the config file to try connect to noip through bond0?