Remote Access Problem

when outside i am trying to access my plex from a plex client. This is not working it is only working via relay. but, the port is open, i can connect via telnet and via webbrowser. i tried manual port and upnp. still plex says that it is not reachable.

any idea how i can debug this?

Private 192.168.1.10 : 32400 <- Public 293.215.293.313 : 32400 x Internet

thanks in advance
Andreas