I have my HomeAssistant setup via DuckDNS so I can access it internally as well as externally and it all works fine.
After a power cut yesterday though the external access has stopped working (internal still OK) and I just get this message :-
I’ve forced an update of DuckDNS to make sure it’s using the correct external IP but that made no difference. It seems like an external connection must get some of the way in to display the HA logo but I cannot see anything in the logs to indicate what might be going on.
If it’s your provider’s router it could be that they made an FW upgrade. If so, it will happen again. That’s how my (ex) provider worked: at each upgrade they just defaulted my router, no warnings, no notifications…
Now at another provider that box is only modem, rest of the job is in my own router.