Does apple tv 4k support amazon prime video in 4K?

I didn't realize this was a difficult question to answer. I cannot get my Apple TV 4K to play Amazon prime 4K streams.

I am surprised no one else seems to have had this issue or has even raised the question.

I still believe.....perhaps the issue is more of no standardized encoding method (H.265).

I have a Vizio 4K TV with the Amazon Prime app built-in, as well as the Netflix app, and can stream 4K from both apps directly on the set without the use of the Apple TV 4K. But I also use Direct TV app and HBO Now and its a hassle to switch back and forth, but it is a valid workaround.

I believe Netflix and Amazon use the same codec to stream 4K (H.265), so may a software update is the solution. I don't believe that Samsung and Vizio use the same codec on video files played from the USB port. Just as Youtube uses a completely different method than either Samsung or Vizio. Apple may be waiting to see what the dominate process will be before committing to hardware changes for any future format. Another Beta/VHS type problem.

Thank you for your reply and I am glad you solved your issue. But that got me thinking........

My Vizio set has only one HDMI input that supports 4K@60Hz and I am already using it for the connection to AV receiver, with the Apple TV 4K connected to that receiver. But it was the HDCP 2.2 part of your answer that got me thinking a little deeper.

The connection with the Apple TV 4K was showing as being 2160p but only when when non-copy protected, non-4K source material was being sent (IE HBO now, Sling TV, etc) and upscaled to 4K. The receiver was made before HDCP 2.2 standard was invented. So although the receiver can send 4K and pass-through 4K, it does not comply with the HDCP 2.2 standard.

A direct connection from the Apple TV 4K to the Vizio on the HDMI port that supports 4K@60Hz and now Amazon prime app (with a 4K program) works perfectly. No more spinning wheel and no more errors. Thank you for helping solve both your issue and mine.