HI, Its not resolved, as best I can tell you have to have the TV on to do anything on the streambar. Even listen to Bluetooth speaker. I tried hooking this up on another newer TV several different ways and cable combinations, and the TV has to remain on at all times. This is disappointing, especially if you want to use it as a bluetooth speaker. If anyone figures out a way, please let me know.
I've been looking into getting a Roku Soundbar to replace a Roku2 with a set of speakers attached to the TV. I was hoping that with AirPlay2 support, you would be able to steam music to the soundbar without the TV being on. I'd rather not have to disable HDMI-CEC as it's useful to be able to power on the TV from the Roku remote.
Maybe it could be a feature request to enable it as a standalone speaker for Airplay. Seems silly powering a TV just to play music through AirPlay?!