If watching TV audio on playbar system - initiating musti will switch automatically from TV to music service.
Switching back to TV can be more complicated. You can go into sonos app and choose TV or you can power cycle your TV so that it loses signal to playbar and gets signal back (initiating an autoplay of the TV).
With Beam / Alexa you have the ability to tell it to Watch TV to switch to TV sound
Respect the Queue (2)Move (3)Beam (1) Era100 (2)ARC (1)SonosOne (1)Playbar (4)Play5 (4)Play1 (3)Play3 (1)Port (2)Connect (1) Roam (2) Ace (1)Connect:Amp (4)Sonos Amp (1)Sub + (9) Echo + Smartthings; (2)Play)