Correct. If you’re using manual port forwards, each server needs its own public port .
There’s quite a number of players when it comes to messing up your remote access and you don’t have control over all of them. If your issue persists, there’s some extended write-up on how to troubleshoot things.
Good point – though the support article you have linked is about accessibility inside your home network. You shouldn’t open those on your router!!
From the article:
Warning! : For security, we very strongly recommend that you do not allow any of these “additional” ports through the firewall or to be forwarded in your router, in cases specifically where your Plex Media Server is running on a machine with a public/WAN IP address. This includes those hosted in a data center as well as machines on a “local network” that have been put into the “DMZ” (the “de-militarized zone”) of the network router. This is not a setup that applies to most users.
