If the update has worked before, and this time you can see that no update has been sent to the ddns server, I think the problem is at the radio site.
The Internet connection can be down so update is not possible, or the router can have hanged up, or there is no power at the radio QTH. The can be many reason but the ddns server is working, there is no indication of problem, so as soon as it receives an update you will be able to connect again.
73 de mike