It is actually a pretty common problem. Most people do not realize that plex specifically mentions in their manual that it works perfectly fine when the server for plex is the same network that is used for your television. If this is the case, you will not have any major problems. However, there is a certain catch to this. If your television network is of a remote nature, then you will inevitably have to modify the settings on your plex to make it work. You will have to change it in such a way that plex now allows even insecure connections so that it picks up the remote signal of the television network. To do this, you will have to simply look up the settings and find the advanced option there and change the setting as specified above.