On my local network, I can access my local self-hosted Confluence server fine from my workstation. However, I cannot access it from the Internet.
I mapped TCP port 8090 on my WAN port to port 8090 on the IP address of my local Confluence server. Both curl's and http requests in Chrome time out. It seems like the connection starts but doesn't complete so that I get a login screen from Confluence.
The browser says
This site can’t be reached
<domain> took too long to respond.
Search Google for<domain> 8090
ERR_CONNECTION_TIMED_OUT