Missing 'Hey Siri' option Mac Studio M4 Max 2025

I have been on the Phone to Apple support for over 1 hour and they are completely stuck and have run out of suggestions, they even got 2 technicians to log int o my Mac to investigate but cannot understand why the option is not there.

They suggested I re-install the OS which I have done but still the same.

After contacting them after the re-install, there were unable to offer a resolve on this.

Anyone else got the same issue or better still a fix.

• macOS 26.1
• USB Microphone, works perfect