I do not know is this related to my upgrade to 0.106.2 but after that DuckDNS stops. I have restarted the addon many times and the result is same with this log below. Until now it has worked just great for me.
Log
INFO: Using main config file /data/workdir/config
ERROR: Problem connecting to server (get for https://acme-v02.api.letsencrypt.org/directory; curl returned with 7)