Hi D S,
Since the microphone permissions are already enabled, could you confirm which Copilot you’re using and whether you access it through Chrome or an installed web app? Also, is the Voice button completely missing or is it still visible but not responding?
If possible, check whether Voice appears when you use the same account on another device. This will help determine whether the issue is specific to the Chromebook or connected to the Copilot experience or account.
Please let me know what you find and I’ll be happy to help further.