If you mean the Alexa ‘wake word chime’ then that is enabled ‘per device’ in the Sonos App ‘Settings/Services & Voice/Voice/Amazon Alexa/zSonos Device Room Name]’.. set the toggle switch to ‘on’ if you wish to hear the tone. (See screenshot).

yes the sonos wake word chime, aka the beep, works but then no response. sometimes the beep doesnt work.

If it’s working sometimes, then perhaps try powering off the speaker fully for a minute or so and see if it works when you bring it back online.

and the toggle is on. btw your pic did not show

The image does show the toggle switch. you probably just need to zoom out/scroll over to the right when viewing the image to see it.