This is a bug in the ddns-scripts package.
We or somebody else needs to dig this bug and look what’s happening inside the ddns-scripts and fix it. I think that we won’t update it unless we have to because of a security issue if it would be found. Hopefully not.
Updater guy (@cynerd ) did some improvements for Updater and prepared pull request for review. My rough estimate is that it can be included in Turris OS 3.12. You can see his response here about this issue.