No surround sound with new system

If they’re working fine with music streaming, it’s actually unlikely to be an issue with Sonos, and more likely an issue with the signal being sent to Sonos from your TV. At the least, I would power off at the same time your Sonos Arc, the TV set, and the Virgin box. After two minutes, power up the Virgin box first, then wait a minute, and power up the TV. Wait another minute, then power up the Arc. Wait a minute for the ARC handshake to complete, then test. 

However, if you’re continuing to have problems, submit a system diagnostic within 10 minutes of recreating this problem, and call Sonos Support to discuss it.

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 Support staff, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.

Thanks for your help. Tried all this and even used the on line help with Sonos. No progress. Wasn’t waiting 80 minutes on the phone for “in person” support so will need to try again. Diagnostics and WiFi all fine. Thinking of going back to my old and trusted Ones with the Beam. Sadly the Subwoffer isn’t supported in Gen 1!!! 

What do you mean by the bolded?  All Sub generations (Sub Gen 1, Gen 2, Gen 3, and Mini) are compatible with the Arc.

What audio input is showing on the ‘Now Playing’ screen in the Sonos App when you’re listening to the TV audio? See screenshot attached.

PCM 5.1 

My Virgin Media Box (TiVo) shows as Dolby Digital 5.1 audio here - try switching the HDMI Input Audio format on the TV HDMI ports to Bitstream and select the Digital Sound Out to “Pass-Through” (if supported) or Auto and see if that resolves your issue.

I’ve managed to sort it. Lots of messing about and studying through both Sonos and virgin. For anyone with a similar predicament;

1. Virgin V6 box needs to be set at “follow content”
2. TV HMDI input needs to be bitstream
3. TV HMDI ARC output needs to be pass through.

Apologies if all this is obvious but my last system didn’t require any of this messing about. 
 

As for the “bolder” comment above, I had a Beam Gen 1 which had compatibility issues with Eros 300 and Dolby Atmos. I wasn’t clear but it after buying the speakers I had to then upgrade the soundbar.

thanks to all who contributed