YunoHost unreachable from outside network

I’ve recently lost external access to the web interface on a raspberrypi hosted YunoHost.
I can access from inside the network.

I’ve forwarded to port 80 but there appears to be no response.
When changing the router to forward to port 81, firefox/chrome get SSL errors…

I can access a rails server hosted on my desktop behind the same router.

What’s the ddx for something like this?

Thanks.

p.s. beginner level experience