Remote (Indirect) Access To PLEX - stable success login after 20x RETRY button

Dears,

It would be delightful to solve my long-lasting issue with remote (indirect) access which behaves very suspicious way.

I have many random devices from several produces and all of these devices I am able to control remotely (WAN) without any issue. However, when I want to watch PLEX remotely I have a connection/protocol issue. Strangely, I am able to connect remotely if I hit the RETRY button in my PLEX mobile app let say 20times. This 20times RETRY is a kind of stable behavior. Once I am able to establish the connection I can do anything with stable streaming “forever”. Once I kill the mobile app and open it again immediately the same 20times RETRY button procedure starts…

I set all needed port forwarding, UPnP on my router, and as the rest of the remote-controlled devices work always without a single issue I assume that there must be some protocol problem on the PLEX side.

Last week, I bought a different router to check that it is not just a one type router protocol - Plex issue, and sadly the behavior of PLEX is just the same - after hitting the RETRY button more than enough times it connects to my computer remotely and from that moment as long as I stay inside the app I can watch any movie without interruption.

To sum it up, to me it seems like a problem of protocol communication inside PLEX, please let me know your thoughts.

Best Regards,
Michal

Duplicate.