Can you open the Sonos App>Settings>Services & Voice>Amazon Alexa and make sure your Alexa devices are enabled.  (Or Google Assistant)

Did you try to remove the voice assistances for both Google and Alexa and re-add them?  Downgrading to S1 is not a common practice and I don’t know if this is absolutely necessary, but this would be my first task in troubleshooting the issue.

UKMedia > yes it is enabled. I can ask questions to Alexa (weather etc...) but when I ask music (form Amazon music) nothing happens. Same fort Google.

melvimbe > I had to downgrade to S1 just in order to calibrate with Trueplay (my old Ipad doesn’t support Sonos S2 app). I tried vocal assistants with S1 firmware with no success.

I have since put the S2 firmware back on but again vocal assistants (Google and Amazon) don’t launch music from their services (Amazon music, Youtube music or any provider).

However Sonos vocal assistant works.

When you say it’s Enabled, do you mean the Sonos Skill in the Alexa App or voice control per device within the Sonos App? Set up Amazon Alexa with a voice-enabled Sonos speaker | Sonos

Ye, I’m pretty sure everything is ok (Sonos skill + configuration) but I will check out tonight.

I have exactly the same problem with Google which does not find the music service (Youtube music).

You were right: it was a problem of association between Alexa and Sonos Beam regarding the skills.

Thanks for your help !