Could you let me know if connecting that sound bar via HDMI does the trick? I have family members with sound bars and/or AVRs, but I haven't had time to visit and diagnose their setups.
There's a Roku secret screen that lets you mess with the remote control settings, including an option to enable/disable "Querying AVRs (instead of TVs)". But haven't had a chance to test it with family members.
[size=120]Why would the Roku channel make a difference?[/size]