Tried using the Plex app on my Samsung TV. - Server status was “Nearby” and the app let me browse the library. However, when I tried to play a film, I got a long wait followed by “Playback Error”.
Tried then using PS5 app., Server status was “Remote”, and it let me view the library and play the film - but presumably not directly on the local net.
OK all devices appear to be on the same subnet. I’ve allowed without auth the 192.168.1.0/255.255.255.0 address - but I’m not too familiar with IPs and I don’t know if this is an IP address for any device on the LAN or if I should be putting in all the device IPs - which change from DHCP