If you can’t login to your Nest account, this could be a result of a permissions access issue with your Google account. You will need to revoke access for the Nest on your account. To revoke access to the Nest on your account, follow these steps:
- Go to https://myaccount.google.com/
- Select Security on left side menu
- Scroll down and find Third Party Access
- Select Nest and Remove Access
Once you have removed access to The Nest, go back to the Nest login page using this link and login again with Google. Your account will now be re-linked.