Help & troubleshooting for channels on your Roku device, including adding/removing channels, logging in to, authenticating, or activating a channel, channel-specific playback issues, assistance contacting channel publishers to report issues, and adjusting channel-specific settings.
This just happened to me just yesterday. My antenna channels don't work by themselves, just a black screen. But when I have my WiFi on I get all my antenna channels just fine. However, when I turn my WiFi off the channel that I had on stayed on, but when I went away from it they all went to black.
This just happened to me just this weekend and must have been due to some update that messed up my Roku TV system.