I have a Roku Soundbar and when I power the device on a watch Roku channels I have no issues. However, when I switch inputs to watch cable TV I lose audio. I can usually flip inputs back and forth a few times to get the audio working. I have the Soundbar connected via HDMI ARC. Any ideas? Of I can't resolve, I am going to return the Soundbar.
I just got my soundbar and I have almost the same issue. My TV does not have ARC, but I have the optic cable connected. Sound works when I'm streaming through Roku but not if I'm watching my regular feed. I see you've had no response for three weeks. That doesn't bode well.