Automatic hardware troubleshooting response instructions found in the TV operating system code:

Apple reportedly only plays 4K movies, but doesn't offer downloads. Cupertino now specifies requirements for 4K streaming in its most recent support document. The document reads: "Apple recommends a minimum speed of 25 Mbps for 4K streaming. "You need to consider this when watching 4K movies on a 4K Apple TV connected to a 4K-compatible TV.

That's not surprising. The higher the quality of streaming video, the faster the internet connection must be. If your Internet connection speed drops below 25 Mbps or the transfer speed drops, the device automatically switches video quality to a lower-quality version.

Apple explains: "When you buy or rent a movie or TV show from the iTunes Store, the device you're using may warn you that it can't play 1080p (HD) or 4K video content. "Instead, your device will automatically play the highest quality version of the video.

If your other Apple devices are compatible, a higher quality version will play.

Before support files appeared on Apple's website, automatic hardware troubleshooting responses found in the tvOS code showed that uninterrupted 4K streaming required a broadband connection of at least 15Mbps.

You can play movies from the iTunes Store using the iTunes store or TV app on iOS, iTunes on Mac or Windows, and iTunes Movies or TV app on the 4th generation Apple TV or later.

As mentioned earlier, Apple reminds you that you can download a local copy of HD movies to your iPhone, iPad, iPod touch, Mac, or PC, and download HDR and Dolby Vision versions of HD movies to your iOS device, but you can't download the 4K version locally.