[solved] DuckDNS + LE + NGINX: "Unable to connect" & "network protocol violation"

I finally understood that I have to use the “NGINX Home Assistant SSL proxy” Add-on and why it is so. :partying_face:
The reason was to be able to use the Android Companion app (which doesn’t work from LAN with DuckDNS + LE)

Now I’m facing another problem: I can only access HA from LAN with http - so I guess NGINX is doing what it’s supposed to.
But, when trying to connect from a foreign network I get following errors:

image

And after pressing “RETRY”:

Oops.
The site at https://xxx.duckdns.org/lovelace has experienced a network protocol violation that cannot be repaired.

EDIT: everything was working as expected before installing the NGINX Add-on

Solved with the help of Remote access for Home Assistant
Port 443 was still forwarded to 8123 :blush: