Hello. I've recently purchased a new Sonos Arc, TV and DVD players. The TV is an LG OLED65CX5LB 65" 4K Ultra HD Smart OLED TV and the DVD player is a Sony UBPX500B 4K Bluray Player. I understand both are able to play Dolby Atmos. I'm using Sky Q for my main TV system and have set it to Ultra HD and Dolby Digital Plus.
I have set up the Arc to the TV using the correct HDMI ARC port and the DVD player and Sky Q to the TV using other HDMI ports. I've tired to watch a Sky Q Ultra HD film (it says Dolby Atmos available in the Sky Cinema section) and Ive also watched an Ultra HD DVD (with Dolby Atmos) on the DVD player. Neither are showing Dolby Atmos on the Sonos App and it says its receiving Stereo PCM when I check it. What am I doing wrong? Thanks.