I have Plex working outside of my network. However, the settings still indicate “Your server is signed in to Plex, but is not reachable from outside your network”
did you put your plex server machine into a DMZ? (you should not)
are you trying to use a custom domain name? (not necessary)
a custom cryptographic certificate? (not necessary)
do you use ‘jumbo frames’ in your local network? (won’t work)
do you use a firewall which inspects encrypted traffic? (won’t work)
have you created a manual port forwarding in your router?
do you use a VPN? (plenty of pitfalls)
In your list the only thing I have done is to create manual port forwarding in my router. After that everything works fine outside of my network. The issue though is that the settings still say “Your server is signed in to Plex, but is not reachable from outside your network”
There are known issues with remote access, be lucky that your only issue is that the indication is wrong. Most of the issues that get posted are the inability to access the server. What version of Plex server are you running?
Version 1.5.6.3790.
It’s weird, as well as confusing, to have the indication wrong.
You can look at the logs and see if there’s any indication as to what’s causing it. Personally I wouldn’t mess with it too much since it’s working.
It is weird.
No public IP address has been reported to plex.tv for your server.
So external access should not be possible at all - simply because an external plex client doesn’t know how to reach your server.
Unless you know your public IP and direct your devices manually to it. But that is cheating 
I’d start by collecting server log files.
- activate debug logging (not ‘verbose’!)
- quit Plex Server
- wait 1 minute
- start Plex Server
- wait 5 minutes
- fetch log files and attach them here
