I have an ARC connected to a Sony 4k TV that has been connected for several years. The sound from the TV stopped playing through the ARC today. I can play music from the Sonos system, just not from the TV. I have read several posts concerning these issues from the last several years, and tried many remedies to no avail.

I turned both off, then on and reconnected the HDMI through the app, but the app says the TV ARC input is now not recognized. I did this with nothing else connected to the TV. Sonos system is up to date. Before, I did this, I selected the external speaker on the TV (main setting is set to Auto to play anyway), but when I played the TV, the TV would immediately switch back to the TV speakers. Now after the above reset, I cannot even hear the audio through the Sonos ARC even if I select it. This seems like an internal ARC issue, since the TV can no longer recognize the ARC.

Please help with this. 

Ok. Not sure how to delete this post. I updated the TV software, and tried the reboot process for both the TV and the ARC speaker and they are now working again. Hopefully this will continue.