Purchased 75” Samsung Tv and new Sonos Arc. Geek Squad set up.  Not getting Dolby Atmos to work. Spent many hours on phone with Sonos to be told system working fine. Spent just as many hours with Samsung.  When Arc is connected through E-Arc the Dolby Atmos on the TV comes up as function not available.  When we disconnect the E Arc cable and unplug the Sonos the function is available on Samsung. Each company blames the other.  What are we doing wrong and which company is responsible?