Troubleshooting : A.N.C. not working
If you are having issues with the Active Noise Cancelling (A.N.C.) functionality, try these troubleshooting tips to resolve the issue:
Push the A.N.C. button for 2 seconds to turn noise cancelling on. Short press the A.N.C. button to toggle between modes.
Check the noise cancelling level in the Marshall Bluetooth app.
If the issue persists, perform a factory reset. This will restore the headphones to their original settings.