I’ve tried re-scanning to no avail. Tuner is updated to the latest available firmware. I’ve also tried uninstalling and re-installing the Channels app completely as well as long-pressing on the tuner and refreshing. I’m thinking it is something with the ATV app since I have purchased the iOS app as well and all of the guide data for the HD channels appears in that app correctly. Any help would be appreciated.
Disregard, I figured it out. For anyone else having this issue: It had to do with my Channels DVR server. After rebooting the Channels DVR server and refreshing the guide data there, everything on the ATV side was good to go.