Samsung Q80 Series 55 - Dolby Atmos settings

[mikejb]

I have a 2019 Q80 Series 55. I've just connected my brand new Sonos Arc - which I'm trying to get working in Dolby Atmos mode.

In the Sound 'Expert Settings' - I do have Dolby Atmos Compatibility enabled, but the Digital Output Audio Format won't budge from PCM. Dolby Digital and Dolby Digital+ are there - but greyed out.

Neither do I have any option to change the HDMI Input Format to Bitstream.

Any ideas / comments very welcome!

[LovepreetS]

Same issue here , Dolby Atmos Compatibility is Greyed out and when you try to click on it 'This function isn't available' is displayed. 

Samsung what is the solution here ? Have I just spent £1000 + on a screen only?.