I used to rely heavily on duckdns and it was great for a time, but moved off them a couple of years ago because resolution became inconsistent. I’ve since rolled my own ddns using a script that utilizes Porkbun.com’s DNS record API.

Not to be confused with white-label products in general

Number go up

Is this the same? Almost every original word is swapped out

Was your old setup using docker volumes? Your old database could be in one

This will be of zero help to you if your registrar isn’t Porkbun, but I’ve recently stopped using DuckDNS in lieu of this.

Duckdns has been inconsistent for me as well for the past year. Have you considered alternatives?

I believe the nameservers are what respond to domain resolution requests. Nameservers not responding could mean they are down. If there’s no backup and the domain is resolved using one of those servers, then that might explain it not working.