Most people don’t have the Sub 4 yet. The ship date isn’t until tomorrow (October 29).

Have you downloaded the latest Sonos app update?

Hmmm….

I’m in the US. The Sub 4 doesn’t ship until 10/29/24. Bestbuy which is an authorized reseller in the US is still only taking pre-orders. 

1. Did Sonos release the Sub 4 earlier in the month in the UK?
2. How long have you had your Sub 4 as you say it “stopped working one day” which suggests you’ve had it for a while?
3. Maybe you’re part of the Sub 4 Beta Team...if so I know you can’t acknowledge it 

So to your question I can’t say one way or another. 

My bad guys, I have a gen 3 in the uk. 
 

I have updated the software to no prevail. 
 

I am now trying different things with Ethernet cables to my Arc and Gen 3 Sub

You’d want to connect the Ethernet cables from the Sub to your router, and not directly to your Arc. The Arc, if you’re connecting it with an Ethernet cable, would also go to your router.