We use Google OAuth to handle hundreds of registrations each day and haven't encountered this before. No errors, no customer reports. Following your instructions, I logged in to my own Google account, removed the connection to our app (via "Third-party apps & services") and then did the login again: after clicking "continue" the screen changes to "loading" instantly before redirecting after a few seconds. There's no ability to click "continue" twice. I then tried to sign up to your app following your instructions and I can reproduce the issue there: the screen doesn't change to "loading" view that I get for our app.
Can you share a copy of your OAuth consent screen settings? Maybe there's an option influencing this behaviour.
edit: we do not use Auth0, our Google OAuth connection is built in house.
Can you share a copy of your OAuth consent screen settings? Maybe there's an option influencing this behaviour.
edit: we do not use Auth0, our Google OAuth connection is built in house.
edit edit: comparing the URLs, our flow redirects from `https://accounts.google.com/signin/oauth/id` to `https://accounts.google.com/signin/oauth/consent` after clicking "continue" whereas yours remains on `https://accounts.google.com/signin/oauth/id` before redirecting to your app so there's definitely something different in the behaviour.