I use google Ouath2.0 with passport.js in my Next.js/Node.js web-app. Registering and logging in works as expected. However, anyone with a google account is able to register, regardless of being in the test users list. The app is unpublished, and so only test users registered by me in the Oauth Consent screen should be able to register and login.
Does anyone know how to fix this? As far as I have understood it, login when not registered as a test user should simply fail. I have seen this asked elsewhere with no answers, and I am not able to contact google as that requires a paid support level.