Perhaps see if simply powering off the speaker, just for a minute, or so, fixes the issue for you.

Nope did not work at all. Still really weird that it works on move and roam and not ONE... Also the box seems to make more mistakes understanding, than the other ones. I really think the microphone is messed up maybe? Could that be the case? But it's weird that it gets hey or ok Google everytime.

I'm suffering the same issue. Checking my Google account activity, it seems possibly that the Sonos One is diverting the response to come from my Nvidia Shield... In my activity history it says Google Assistant SDK when a question is answered by the Sonos, but when I get nothing back from the Sonos it says Android TV in my Google history.