Plex - "Not available outside your network"

I just installed a new hard drive in my machine, and installed and configured Quickbox for the first time on my network.

I’ve got Plex configured, but I’m still struggling with remote access. I’ve claimed the server, got remote access enabled, and am not specifying a port manually. I have been able to confirm that i can’t connect from outside.

I am running Ubuntu 16.04 LTS
machine is an AMD 8 core with 32GB RAM and 250 GB SSD for the OS
It is behind an ASUS router with the firewall and UPnP enabled

I cannot even connect from plex.tv