UPDATE 1/14 12:30PM: The FYC Desktop App has now been fully updated and downloads and streaming have all been restored. You MUST update your app to Version 2019.1.1 by downloading the new version from https://wbfyc.com/app/ Thanks for your patience!
If the Apple TV doesn't respond to commands from a device with the remote app installed, the device may be unpaired or it may need to be re-paired.
Device Is Unpaired
You can check to see if your phone or tablet is listed under 'Remote App and Devices' by going to Settings > Remotes and Devices > Remote App and Devices. If it is not listed, you will need to pair the device.
Open the remote app and select 'Add a Device.' Open 'Remote App and Devices' on the Apple TV and select the device. Enter the four-digit number provided by the Apple TV into your mobile device.
Device Needs To Be Re-Paired
Select the device in 'Remote App and Devices' and choose the 'Forget' option. Next, using the steps listed above, re-pair the device.