Apple TV 4K no Dolby Vision after connecting via Soundbar
As most of my Apple TV 4K movies are in 4k with Dolby Vision and Dolby Atmos I wanted to extend my sound system as my LG TV only supports Dolby Vision/4K/HDR (and works perfectly fine with HDMI connection from ATV4K to TV) but not Dolby Atmos. So I searched for a Soundbar with Dolby Atmos and 4K Passthrough and the LG SN7CY has that and is Dolby Vision compatible... Bingo.!
As per the instructions on both Apple and LG I connected the ATV4K to The Soundbar (to get Atmos) and the Soundbar to the TV using the Soundbar Passthrough, simple enough but it seems upon doing so ie playing a movie with 4K Dolby Vision and Atmos, the TV switches to 4K HDR and not Dolby Vision? I went into ATV4K Audio/Video settings and noticed that all the Dolby Vision options are gone, leaving just the various versions of SDR and HDR format.
Am I missing something somewhere, surely someone has this type of setup?
Hope you can help...
Kindest regards
Apple TV 4K, tvOS 13