I have a Sonos play bar and 2 Sonos Ones for the rear channels. If I say "Alexa, play Billy Joel" while I'm watching TV, it switches and starts playing music. That's great. Now I want to return to the optical input of the Play Bar and start listening to the TV audio again. What do I say to switch it back? The only way I have found is to get out my phone and go through the app to switch it back.