How are the speakers connected to the TV and to the network? Kindly sketch out your configuration. 

It looks like your system is working as intended. All stereo sounds from the TV are mostly played on the soundbar with some “pseudo surround” on the surrounds. Music from other sources is played through all speakers when the system is set to “full”.

I can't sketch but can try to explain my connection in detail. Tv (sky glass) is connected via hdmi arc to my sonos beam. I have a sofa opposite my TV which has two sonos one sl speakers on either side. Tv, beam and sonos one sl are connected via WiFi. Sonos one sl speakers are connected as a surround sound system to my beam over WiFi.

Its what I would call a typical living room home setup.

If I try airplay or open Spotify and play music directly to the beam the surround sl speakers work along with the beam. But if I try to use my sonos surround system as the external audio output on my tv, audio only comes out of the sonos beam, there is no audio coming through either of the sonos one sl speakers.

Hope this clarifies my setup 

All very standard then. Do take note of the comment from @106rallye. A lot of broadcast TV content is in stereo and contains no surround information. Have you tested with a source which plays in Dolby 5.1?

Hi 106rallye 

I have set the option to full sound and not to play ambient sound.  I've even tried modifying the TV level of the surround speakers directly in the sonons app, setting it to maximum for TV and music. 

no sound not even an ambient sound is coming from the sonos one sl speakers when I try to play audio through the TV. 

Could it be the TV itself? Are there any issues with sonos beam and sky glass TVs?

Hi 106rallye and ratty, not sure what happened but I reset my sonos speakers re-powered my tg and it started working.   

Not sure what I did, but thank you for taking the time to respond

For any others coming upon this thread, the ‘ambient/full’ settings have to do with streamed music only, and that setting has no effect on a TV input. When using the TV, in order to get sound from the surround speakers, the source on the TV must be a 5.1 source of some type, and must be being sent to the Sonos.