In my case, there is no IP change. However, the TTL of entries seems to be 60 seconds and when Cloudfare/Google asks for the new A record, it sometimes fails. I am getting this error message from Cloudfare when I try to solve host.sub-domain.duckdns.org
EDE: 22 (No Reachable Authority): (time limit exceeded)
I have a domain… but I think DynDNS is not always available for every domain or by every domain seller?