Dolby Digital - Sonos Arc - Apple TV - e-ARC - Samsung

Hi everyone,
 

Just installed my new ARC sound bar.

My setup is Samsung TV with e-ARC, Apple TV 4K last generation.

My TV is set to (HDMI-eARC Auto)

Apple TV is set to “Change Format - No"

When playing a Dolby Atmos movie on Netflix from Apple TV, I get Dolby Atoms signal on my Sonos App.

When playing a Dobly Digital movie on Netflix from Apple TV, I get PCM Stereo.

I couldn't find how to get Dolby Digital signal in Sonos App…

Appart from Dolby Atmos, all other contents are playing in PCM Stereo. 

Thanks for you help guys.