I’m fairly new to the HA and i just set it up with duckdns and i can reach my HA from outside but i can’t use hassio.local:8123 unless i type the exact IP address.
And a second issue i’m having is when i connect through web ssl is working but when i connect via local IP, my browser warning me about “Certificate Invalid”.
If you have a base URL set with SSL, you always need to access over https even if using the local IP. Your browser will warn you about that (as you’ve noticed) because the SSL cert is for your duckdns domain, not your local IP.
You can avoid this by using a reverse proxy for SSL (such as NGINX) and not setting a base URL. Remote access is encrypted, local access is unencrypted. That’s what I do.
If you have a decent router, ie ubiquiti you can add the external address to point to your internal ip.
The other option is use the dnsmasq add-on and configure your router to issue DNS ip pointing to your hassio ip instead of the routers ip or the external isp’s dns servers, just primary. Then any client connecting to you network will be able to resolve the external name internally