Not nearly enough information to hazard a guess. I’d have thought CEC wasn’t turned on, but then the Sonos wouldn’t be seen by the TV and vice versa. I can’t think of a reason why both would see each other, but not work. Have you rebooted the TV by unplugging it from the wall for two minutes?

I would recommend that you submit a system diagnostic , and call Sonos Support to discuss it, or post the diagnostic number here for a Community Moderator to pick up.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

When you speak directly to the phone folks, there are more options available beyond just the diagnostic analysis.

Thanks for the suggestion Bruce. Did the whole reboot routine but to no avail. I’ll give the system diagnostic a shot. Frustrating when these things don’t work as advertised. 

It’s somewhat unfortunate, but as technology progresses, so does the opportunity for failure. Long gone are the days of wired hi-fi equipment, now we need to be worried about networking, HDMI, CEC, and a plethora of other potential points of failure.