SOLVED!!!
Apparently Google has added a little splash screen to the flow that happens before it calls https://[YOUR _DOMIAN]/auth/authorize. In order for this info screen to work correctly, you now must complete the “Enter information required for the Actions directory” portion of the Actions setup overview. This requires you to provide:
- A description of your app
- A logo image for your app
- Your name and email
- A link to a privacy policy
For the description I wrote:
Short: “Connect Google Assistant to a private Home Assistant server”
Long: “This Action is intended for personal use. It exposes smart home devices controlled by a local Home Assistant server to Google Assistant and by extension the Google Home mobile app.”
For the logo, my house had one already, so I used that. Otherwise, just upload the HA logo.
For the privacy policy, create a Google Doc that can be viewed by anyone with the link that says:
" This application is intended for the private use of its developer. Any unauthorized users which connect to this service should have no expectation of privacy or protection of their data."
After I had all that entered, I could link GA to HA without issue. I need to go to an appointment now, but sometime this evening or tomorrow I’ll submit and issue ticket to update the manual configuration instructions.