No http/https port forwarding available


I tried to configure port forwarding for http/https to the installed Wordpress App for access from the Internet, according to

I selected default service scan, but there is no http nor https service listed in the result. Only ssh and ftp are listed and i can confirm that ssh is working as expected.

I can not use the mycloud service to access the mycloud from outside, because my provider does carrier grade nat (CGN) and my local network is only available by ipv6.

I’m sure that my router/firewall is configured correctly, because I am able to ssh from an outside server and can do a tracepath on port 80 'till the mycloud. But when I try to call it via curl, the apache2 server responded with an http error 403 (Forbidden).

Configuring a manual service port forward for port 80 gave the exact same result.

Any help is appreciated.