Could be an issue if you have no port opened in your router:
- you connect e.g.
192.168.1.56 - NC will redirect you to ddns nost
- ddns host is bounded to your externals ip, e.g.
100.100.100.100 - your browser will try to access
https://ddns host/on100.100.100.100 - If 443 port closed - you failed to connect.
That is correct, now you will be redirected to https://ddns host/ on 192.168.1.56 instead 100.100.100.100. You can also use your hosts file locally without any modifications on router for such kind of things.