Update: I uninstall the Google Home app from my iPhone and reinstalled
it and allow all the notification, camera and microphone permissions
again and it fixed my problem I mentioned in my comment above.
I just purchased Nest doorbell (battery) 2 days ago and noticed today
that my voice is not heard on the doorbell. I use Live option on Google
Home app on my iPhone 12 pro max and no way I can fix it. It looks like
lot of other people having same issu...