Dynamic DNS name propagation errors

[Lynnehawk 1]

I'm trying to figure out how to use an SSH tunnel to access my home computer when I'm away. I used AirVPN to forward a random port, and then set that as my listening port on my SSH server. Several hours later, I tried to connect from another location, but my SSH client didn't recognize the hostname (****.airdns.org). I logged-in to this site and checked the Dynamic DNS Name Propagation. Each DNS server has a red error message. AirVPN DNS, Google, and OpenDNS simply say "EMPTY", but the other two give rather specific error messages.

OpenNIC says:  ";; Connection to 109.235.51.12#53(109.235.51.12) for ****.airdns.org failed: connection refused."
DNS Advantage says:  ";; communications error to 156.154.70.1#53: connection reset"

I have absolutely no idea what any of it means, but I can tell that my home computer is still connected to an AirVPN server.

[Lynnehawk 1]

I'm not sure what happened, but I tried a different combination of ports, and now it works!