I have a problem with my rasplex. They aren't detected on the plex web app. They can play media without any problem but i can't control them with my computer.
I think the problem is with my network because I have a router between the PMS and the rasplex.
The normal solution to your problem would be to NOT use a second router to create a second subnet. The name address translation (aka: NAT) between the first and second subnet is what creates the problem.
I don’t understand what real purpose that second router serves in your LAN.
If you just need additional ethernet ports, just replace the router with a network switch, or just use the second router as a switch (disable its DHCP and connect one of its LAN ports to a LAN port of the first router, leaving the WAN port of the second router unconnected. Either way, with switch or switch-simulating router, all your LAN units will be on the same subnet and able to ‘see’ each other properly.
If your second subnet does serve some important purpose (which you never described), then other methods may be needed, such as extensive port forwarding configuration for the second router. But without knowing more about its purpose I can’t advise you properly on this.
