Apple TV booting Sonos off Airplay

Hi all,

Seeking some advice. We have flawlessly used Airplay via Apple TV to Sonos One for some time now, but in the last fortnight, it's stopped working.

I've spoken with Sonos and ruled everything out from the speaker set-up, Sonos still plays from my iPhone and MacBook without issue so it's only Apple TV that is the problem.

I've re-set, re-checked and done everything I can think of and read of, still no love. Our internet set up or house set up has not changed. It just stopped working suddenly.

Does anyone have any idea what could be happening?

Airplay on Apple TV can see Sonos but when I select the speakers or even one single speaker it allows me to check the box, then reverts back to the TV speakers.

Help is greatly appreciated!

Thank you in advance.