Just change the DynDNS check interval to off, and that's it.
Actually, it is also completely harmless to let it continue to run, since it will never
make a change, anyway. So there is no rush to change it.
Do NOT enter anything in the external IP/host field! You don't need to enter your
external IP number on the radio side at all, but do so on the control side RRC in the
"SIP contact" field under the radio settings.
73,
Mitch DJ0QN / K7DX