How to fix Sony Bravia/Sonos sound stops working

We have a Sony Bravia television connected to a Sonos Beam which in turn is linked to a couple of Sonos Ones. They have been working fine for quite a while but suddenly lost sound.

First stage was to check the Sonos was working. I played music via the mobile app and it was fine.

Next, to check the TV. I noticed that when I moved through the options (under Home) I was getting sound but through the TV speakers. I went to the “Audio Output” settings and changed it to TV Speakers and that worked - sound came from the TV, not the Sonos - as expected.

Next back in the Sonos App I went to Settings then TV Setup. Following the steps it said that something was interfering with the HDMI ARC connection.

Back to the TV. Powered it off then left it for a couple of minutes and restarted. Went into Home/Settings/Watching TV/External Inputs and turned off the “Bravia Sync Settings” and then back on again. I went to the “Bravia Sync Device List” and nothing was listed.

This is what eventually fixed it. I clicked “Enable” - still nothing listed. I then unplugged all the HDMI cables except the Sonos. Suddenly the Sonos appeared in that list. I was then able to plug the cables back in again and it all worked.