Hello @Missionsparta, thank you for the post!

I just tried a couple movies and TV series from the Prime Video app on my setup, that have the label “Dolby Atmos" and can see the correct label on the Sonos App as well.

Can you please give me some examples where you are facing this issue and I will try to reproduce?

Bare in mind that the Prime Video app required an update for me on my TV since it has been a while since the last time I watched something there.

I am 99% positive it is on the Prime end, but I noticed it like a day after updating to 15.10, so I thought I'd see what others are seeing. Titles like Jack Ryan and Candy Cane Lane clearly state Dolby Atmos on my screen listing but play in 5.1. I have called their support and that was a nightmare. After about 5 minutes of confusion I became aware that they thought the show title was Dolby Atmos. Then when I explained to them what it was they kept asking me to try stuff and see if I got sound. I repeatedly had to tell him it wasn't about lack of audio but the audio format being pushed out and/or received. He then asked me how I knew it was suppose to play in that format and I explained the icons on a show or movie's page. In the end I finally convinced him to move it along to a higher level support and they said they'd get back to me. 

In the end, any title I try does not work now. I'm going to assume it is on Primes end as of now, but it really sounds like I'm the o ly one effected. No recent Apple updates in the past week or prime app update, only the Sonos 15.10 is why I was asking in here. 

Thanks for the help.