Macbook Pro 2021 HDMI Dolby audio output

Hi All,

I have an 2021 MacBook Pro M1 which I occasionally hook up to my AV Receiver (Yamaha RXA820). The receiver support HMDI 2.0 and Dolby Digital Plus (EC3). However I only seem to be able to output Dolby Digital audio content (AC3) to the receiver. EC3 is not recognized and then it reverts to PCM. I can of course setup the Mac to provide multi channel PCM output but then the Mac is decoding the Dolby signal and the receiver does a better job on that. I've checked everything (including cable). I've done some searching on the net and found this on Reddit:

https://www.reddit.com/r/AppleMusic/comments/svja8t/dolby_atmos_via_hdmi_on_macbook_pro/

In this thread it is claimed that the Macbook Pro can't output anything beyond Dolby Digital. It does seems like it but that would not be very PRO if you ask me. Can anyone confirm that the Macbook Pro can output digitial audio over HDMI beyond Dolby Digital?

Kind Regards,

André