Intro
The last few days, my Google Assistants frequently responded that they could not reach Home Assistant. Earlier, this happened only now and then. Since last week, it started happening multiple times a day. Repeating the command usually worked.
I thought I’d try Local Fulfillment, to see if that might help. Everything still worked, however commands somehow would not fulfill locally and the intermittent service didn’t get solved.
The issue
As of yesterday, Google Assistant could not reach my Home Assistant anymore at all. Therefore, I tried to unlink and setup the connection anew. However, I cannot reconnect to the Home Assistant anymore, nor can I on an other account where I shared the Google Action (in test) with.
When adding Home Assistant in Google Home, I can see [test] Home Assistant, I get to the Home Assistant login screen, where I enter my credentials. Then a Google loading animation appears and I get sent back to the list with all available ‘works with Google’ apps list and get a message in the bottom ‘Could not reach [test] Home Assistant. Please try again’. But trying again does not work 
What I’ve tried
I’ve deleted the Home Assistant ‘app’ from my Android starting screen. I’ve even created a whole new project and started in Home Assistant anew (so configured to the new project). I’ve followed every topic here and filled in all required information in the Google Action (as of this thread: Can no longer link Google Assistant - #34 by danfmc).
I’ve looked in my Nginx Proxy Manager logs and cannot find anything going wrong, I see the Google project connecting to the API. Also, my DNS via Cloudflare still is working fine for the rest of my devices. I’ve tried to disable the proxying via Cloudflare (so only DNS) but that didn’t help either.When disabling the proxying I cannot reach any of my websites, probably because of certificates. I can reach the Google Assistant API of Home Assistant (with a 503 Method not supported). Everything seems to be in order, except that Google Home keeps repeating that it could not reach Home Assistant when linking.
So in all, tried to start almost from scratch and still it is not working. How can I further check what is going wrong? Any ideas on fixing this?
