Hi there! I understand you're having some trouble with the Magellan Channel app on your Apple TV, where it only shows the left-hand vertical menu. Let's work together to get this sorted out.

First, can you let me know if you've already tried any troubleshooting steps, such as restarting the app or the Apple TV itself? This can often resolve minor glitches. If you haven’t, here’s a quick step-by-step guide to follow:

1. Restart the Magellan Channel App:
- Double-click the TV button on your remote.
- Swipe left or right to find the Magellan Channel app.
- Swipe up on the app to close it.
- Open the app again and see if the issue persists.

2. Restart Your Apple TV:
- Go to Settings > System > Restart, or simply unplug it for a few seconds and then plug it back in.

3. Check for Updates:
- Ensure that your Apple TV is running the latest version of tvOS. Go to Settings > System > Software Updates, and select Update Software.

If you’ve tried these steps and the menu issue continues, it might be worth uninstalling and reinstalling the app. Here’s how you can do that:

1. Highlight the Magellan Channel app on the home screen.
2. Press and hold the touchpad on the remote until the app starts to jiggle.
3. Press the Play/Pause button, then select Delete.
4. After deletion, go to the App Store, find the Magellan Channel app, and reinstall it.

If these steps don’t help, sometimes this can be an issue with the app’s compatibility after updates, which can happen. You can check discussions from users facing similar problems here or refer to support from Apple for further assistance.

Let me know if any of these solutions work for you, or if you need more help!