Channels not working on anything but Win PCs

Recently set up a Plex server on a Win10 PC (Quad core/4GBram). It is generally working good, but the 'Channels will not play video on anything but a PC. The videos just stay at the buffering state on iPhones and Xbox360's. I have 2 Win10 boxes and they seem to work OK there. I have tried several channels. Common ones like ABC and CNN. I also am trying to get the Hdhomerun channel to work.

Any ideas

Thanks

Apollo