So… let’s go down that rabbit hole.
Did you already have a look at the related troubleshooting support article?
https://support.plex.tv/articles/200931138-troubleshooting-remote-access/
There’s also a guide with some more details on how to troubleshoot remote access issues. In order for others to help, you’ll need to share the individual output of those steps, e.g. starting with can you actually see/access your router’s forwarded public port from outside your home network (e.g. using a service like canyouseeme.org)?
