Tv app displays a thin grey line

Hello NZfan,

Thank you for reaching out to Apple Support Communities.

Let's troubleshoot the Apple TV app using these steps:

"If the video quality is bad or it stops playing

1. If multiple people on your network are using the internet, your connection speed might slow down. Ask them to temporarily pause their internet activities.
2. If you're using a smart TV or streaming device, turn it off and back on again. If you're using an Apple device, restart it.
3. Tap or click the download button to try downloading the movie or TV show instead.*

* You can't download movies or TV shows to Apple TV, smart TVs, or streaming devices. You can download HDR content only to certain iPhone, iPad, and iPod touch models. You can't download 4K video content to any device."

More details can be found here: If you can't watch or stream movies and TV shows in the Apple TV app

If the issue persists, can you provide a few more details? Is your TV up to date? Does the same thing happen if you delete and reinstall the app? Also, when did you first notice this?

Cheers!