I selfhost some tools and use duckdns for names resolution but it does not seem to be working today. My ISP updated some things on there end last night and I updated my local unbound server so I’m not sure which if either of these is also playing a role but I cant seem to access duckdns. I have tried to connect to it on my phone network outside of my isp’s control and cant which leads me to believe that duckdns is down?
Duckdns has been inconsistent for me as well for the past year. Have you considered alternatives?
I’ve had major problems for days like half a year ago. Switched to dynv6.net with no issues so far.