Last month, after upgrading Home Assistant to the latest version. tts.google_say stopped working. Every call to this service takes 3 to 5 secs and nothing happens.
To fix this, Google Home needs to be manually added to Home Assistant as a media player.
media_player:   
  - platform: cast   
   host: 192.168.1.xxx   

IP address is your Google Home"s IP address, recommanding setting up fixed IP in your router...