Beam worked fine on previous LG, this was replaced when the LG started losing pixels.
LG OLED55C34 took several attempts for Arc HDMI to connect, after a few days Beam sound lost. The mute icon showed on the screen. TV sound was fine. Changed cables with no impact, disconnected everything, connected Arc cable and used the smart TV Netflix still no sound. After much fiddling it finally connected. Al good for a few days then Beam lost again and connection couldnt be revived.
I then tried the tv Optical connection with the Sonos adapter, connected immediately. Me thinks therefore that it may be a TV problem ?