Just to add that I have done everything suggested by just about everywhere. I suspect the eArc port on the Beam has an issue. Odd that the TV sees the Beam on eArc HDMI 3 port and lists it in the Bravia synch list shows that there is some connectivity. But the Sonos app and the Sony setup test both fail. And of course no sound. Spotify plays ok so the Beam does work

ill call Sonos but I suspect I’ll end up taking it back to John Lewis. Maybe we can test it on one of their display Sony TV. Before I swap it out for another Beam

Its working

I decided to try one more time. Particularly the initial connection process. As in power off, disconnect everything. Plug power back in and run the TV setup in the Sonos app. Only plug in the HDMI and only the HDMI when prompted by the app and press continue. It worked after doing that

Such a precise and “delicate” process rather than the usual plug everything and it works approach was surprising. But anyway it’s all working and the sound is spectacular

Sad news

It stopped working. I turned the TV off and an hour later turned it on again and no audio. Once again Beam shows up on the TV as a connected device but the Beam won’t play ball when enabled from the TV app or the Sonos app. 
 

So ran through the whole setup again and it worked. However, couple of hours later turned TV back on again and yes you guessed it no audio. Tried the whole setup several times without luck. 
 

The fact that the TV sees the Beam and also sees it in Bravia synch tells me the TV is fine but I suspect when the TV is turned off and the Beam loses the HDMI connection it loses or resets the connection data for the TV. Like it was a new install. To me this looks like a software bug. Could be hardware. But I know the TV works ok as my amp and Apple TV work fine on the same HDMI port. It also plays a very ancient Sony stereo soundbar fine but the sound is truly awful

I might try another Beam but I’m inclined to cut my losses and get a Bose. How frustrating. Anyone any tips ? I’ll call Sonos but not expecting much other than what I’ve tried

What did Sonos Support say, when you called in?

Looks like the same Sony problem as mentioned here: 

Sonos Beam is just not very good for the job it supposed to do. When I bought mine, it was a nightmare to add it to my SONOS system and to get it playing sound from my Samsung TV. I got there eventually, after a long call with Sonos Support, but it never worked properly imho. (Volume control was only possible with the SONOS app and TV or set-top box remote volume controls would not work.)

I bought a new TV this week. LG this time. Guess what? Beam won’t play sound from TV. 

I reconnected to my Samsung. No changes to the settings since it was connected a few hours earlier, but now it won’t play sound either.

I was an early SONOS convert and now I hardly ever use the system because half of my components work with system one and half with only system two. That obviously defeats the objective of a supposed multi-device system that should work throughout the home.

I used to promote SONOS to anyone who would listen. I no longer have anything good to say about the brand I’m afraid.

On the other hand my Beam (Gen 1) always worked great with both Samsung TV’s and a TCL it has been connected to. Setting it up was no bother at all. Same with my Arc Ultra. I’m not saying this is you, just that our experiences setting up and using Sonos differ.

Lucky you. Mine is a Beam Gen 1 also.

Out of interest, are you connecting using optical out or HDMI Arc? The instructions for both of my TVs advise the use of optical. SONOS instructions prefer HDMI Arc. I’ve tried both.

It’s a speaker connected to a TV by a cable. What’s so difficult that it doesn’t just work?