Sonos devices are meant to stay powered on.  They automatically go into a low power state after a period of no content (as does every other modern appliance, i.e. your TV is not truly “Off” when it turns off).  Actually powering Sonos devices off when not in use would require them to fully reboot on turning on, a process which takes a while and doesn’t lend itself to quick access to music and/or TV content.

Thank you!

I recently upgraded to the Arc Ultra soundbar. During setup, everything went fine until I attempted to complete the "tv setup" which connects the tv with the soundbar. I kept receiving an error message that indicated another home theater component was interfering with the connection between my LG C2 tv and the Arc Ultra soundbar. Without this connection,  when I turned the tv, cable box and soundbar on, the sound did not come for 2 to 3 minutes. After disconnecting all other home theater components, I was able to determine that it was the Spectrum cable box that was interfering with the "tv setup". I was able to resolve this issue by purchasing a Lindy HDMI CEC less adapter, female to male for $22.00. This adapter eliminated CEC from the cable box to the tv and solved the problem. Now when I turn an the tv, cable box and soundbar the sound is immediately audible.