Here’s my setup:
Sonos Arc - connected through supplied HDMI cable to ARC port on my TV - Vizio P55-F1 (2018)
Issue:
VIzio remote control will only turn down the volume, not up. Power Cycle seems to resolve for a short period of time. Also it seems I can only turn the volume up if the Arc sees the IR signal from the remote, If I make sure only the TV can pick up the IR signal it notices that I have pushed a button and displays the volume level on the screen but will not increase or decrease the volume. TV volume controls work fine if the Arc is unplugged. Also noticed the volume controls on the back of the TV won’t turn the Arc volume up or down either.
Hoping someone can point me in the direction of a fix, or at least wanting to see if others are having a similar issue.