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.
Try removing the channel from the Roku home screen by navigating to the channel tile, pressing the * key on your remote and choosing 'Remove channel'. Then restart your device from Settings>System>System restart. Once your player starts up again, add the channel back once more.
For more information about that channel's authentication and functionality, you'll want to contact Fox News support directly to inquire further. Many channels on Roku are developed and maintained by the channel provider themselves.
Following the instructions from ROKU to my post, I now have two sets working without having to sign in after a time out. Deleting Fox News, restarting ROKU and adding the channel back corrected the issue for me.