Siri not working on Sonoma with Mac Studio & Studio Display - noise when icon/button pressed
All settings are correct and have tried toggling Siri. WiFi and ethernet are connected.
When I either click the Siri Menu Bar icon or press and hold the Mic/F5 button I just get an odd sound but no response from Siri. It does not display any text (I tried turning the option on to display Siri's words).
When toggling Siri OFF and then ON, and then turning the 'Listen For' options on it goes through the learning exercise. Not sure why but it will repeat this if I toggle the 'Listen For' off and then back on - surely it does not need to re-learn.
Please don't direct me to any Apple Support documents - I've been through them all.
And yes, the microphone works fine in e.g. Zoom.
What else could be wrong?
Mac Studio, macOS 14.5