Which model TV? How is the setup not working?

I got my Sony replaced its  an 850,   same tv as before just got a replacement,  so I wanted to move the beam from optical to hdmi arc and it won't do that  no sound, but the hdmi arc works for other connections 

I also have the beam hardwire to a mesh Eero pod 

No sound could be a supported audio format spat. I hear about occasional bad experiences with 850’s. I don’t know the percentage or what the magic solution is. There are various reported problems. Some users simply reboot the TV, others have factory reset the TV after downloading the latest SONY firmware. Make sure that CEC is enabled on the TV.

Here is a discussion about supported formats.

Using a SONOS controller you can go to Settings → System → About My System and view the audio format that BEAM is receiving.

Maybe something here will help, however, do not Factory Reset the Sonos system without further consult.

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Just to make sure that there is no misunderstanding, there is only one HDMI connection on the TV that supports ARC. This port must be used to made the connection to BEAM.