Set the TV to these settings:

HDMI-eARC Mode: Auto

Digital Output Audio Format: Pass-Through

And play the film The Tomorrow War from Prime Video.

I can’t change the Digital Output Audio Format to “Pass-Through”. Error- “Current audio format cannot be passed through with an ARC connection”.

I am playing the Amazon Prime Video App in Samsung TV and NOT through a Fire TV stick.

Does the TV allow you to change the Digital Output Audio Format setting while you are playing The Tomorrow War on Prime Video? What audio format is displayed in the Sonos app when playing this film?

What audio format is displayed in the Sonos app when playing The Tomorrow War?

Dolby Multichannel PCM 5.1

Set HDMI-eARC Mode to OFF and test the film again.

I did try that. Then I get “Dolby Digital Plus 5.1” still no Atmos

I am starting to suspect that I will need an external streaming device to enable the pass-through mode on this TV

I have a feeling your TV doesn’t support Dolby Atmos audio from the TV’s Prime Video app.

Are there any other apps you can test (Disney+, Netflix premium, Max, Apple TV+)?

Will need to upgrade my Netflix subscription. Will try and post the result. Thank you.

Documenting for anyone else who might be having this issue. I bought an Amazon fire stick and attached it to HDMI port on the TV. TV settings as above. Prime Video on fire stick gives me Dolby Atmos audio option for some of the content. Playing “Jack Ryan” with Dolby Atmos option selected in Prime Video gives Atmos output on Sonos. Thank you