I just got an Android TV and set it up. When I hold the google button or press the microphon button on screen, it doesn't pick up my voice. The mic flashes red and it doesn't pick me up. When the google voice prompt is on screen, the dots dont bounce to notify that it hears me.
Edit: Ok I found the problem. I was missing it saying "Hold menu button to pair Bluetooth remote", so holding the button for menu on the remote connected it in some different way and now voice works
I had that when I first set up my Android TV. Check for updates first then restart the TV. It should be an option to perform a restart in the menu, rather than doing it manually. This sorted it for me.
Edit: you just press the button, not hold it. Took me a while to realise that!!