My set up hasn’t changed for around 3 years. My SkyQ and TV are both configured for optical output and the wiring and configuration have not changed. Last night around 10pm, the sound stopped working through Sonos and I had to revert to the TV speakers. I switched everything off and on again and it still doesn’t work. 
 

The Sonos system works perfectly independently of the TV. 

Has anyone else seen this or have any advice please?