I'm having this same issue. From Siri results; I can play movie trailers on: iPhone, iPad, iPad Pro, and MacBook Pro. However I can't play movie trailers on either of my AppleTV 4K boxes. All of these devices are connected to the same home network, they can all play movie trailers except for my two AppleTV 4K's. Which means this appears to be unique to the AppleTV's tvOS.
To reiterate what OP @drewstg and @fredbonn said: On an AppleTV box, if you manually browse to a movie that's in the iTunes Movies app or the TV+ app the trailer will play, however if you search for the movie using text search or voice (Siri) which is by far the most commonly used way to find a movie you're looking for, then the trailer wont play and it just brings you back to the Home Screen of the TV+ app.
Things I've tried:
- Rebooting router & cable modem
- Resetting router to factory default
- Unplugging power from AppleTV boxes for 10mins, plugging back in
- AppleTV's connected via Wi-Fi
- AppleTV's connected via wired Ethernet
- Updating tvOS to latest version (14.4)
- Resetting AppleTV's to factory default
- Logging in to AppleTV with a different AppleID
- Changing DNS from CloudFlare (1.1.1.1) to OpenDNS (208.67.222.222)
- Changing DNS to Comcast (75.75.75.75)
- Adding AppleTV to DMZ of router
None of the above steps resolved the issue. Many other people are experiencing the same problem. How can we get the attention of someone at Apple to take a look at this since it appears to be a software issue? Are you able to help escalate this @Jeff_W ?