I would have refreshed my old topic, but I couldn’t - but still have the same issue. When travelling I can’t watch anything from my server at home. When I look at the local Web Gui (connect via VPN to check) there is often a red warning sign against “Remote Access”, when I click on Remote Access it turns green instantly and remote clients could watch movies or tv shows from Plex. That works as long as I watch. After a while, without watching, it falls back to the state of the red warning sign. Port is manually forwarded in my Router and so it is setup in the GUI of Plex - as you can see.
I would have to check the settings once I am back home. But, I just noticed that I don’t even have to connect to VPN and use the local IP to manage, it is enough to go to app.plex.tv and go to my server - first to see the red warning sign, which turns instantly green, when I click on it. Then any player could play.
But if friends (shared library) would like to watch something, that does work - because they can’t access my servers settings. I really don’t think that this is somehow network settings related.