Google Assistant can no longer sync my devices

“There was an error syncing” the name of my Google Assistant integration.

There is absolutely nothing in the log on Home Assistant. I can use Assistant to control anything that has already been added. I can access my Home Assistant instance externally. The security certificate is valid and up to date. I have reset all my Google home devices to remove my nephew’s account that he added while visiting (long shot but it was the only recent change). I have thought about removing and re-adding HASS to Assistant, but considering the consequences of that if it still doesn’t want to sync, I don’t want to try that unless I have completely exhausted all possibilities.

I couldn’t find anyone else with this problem but I just may not be searching for the right terms.

OK I solved the problem. It was an interesting problem with a very simple solution.

So I had no idea that syncing devices required an API key. Clearly through some glitch when this feature was enabled on Google’s end I was able to sync my devices without changing any settings on the Developer Console or on HASS.

I noticed the changes as I was reading through the updated Google Assistant docs for Home Assistant.

I enabled the key and added it to Home Assistant and poof, everything broke. No device control through home assistant anymore. At that point I had nothing to lose by removing and re-adding my HASS integration from the Home app. And viola, everything now works again.

Clearly an edge case, but just in case someone else had this issue I wanted to share.