You need to enter your local IP and subnet in the server and on the client you need to change the connection to preferred secure. Do a search and you should find the direction.
My android TV, Shield, and Fire TV’s work without Internet. It does take a couple of minutes when you first launch Plex for it to load. I am assuming it is trying to connect over the Internet and it has to time out before it loads.
Hi @LittleBro, yeah unfortunately as per the link @Alucard1 sent it does state that most “Smart TV” Apps will require an internet connection, see reference image with details below: