I used CEF for a project and Google is detecting CEF via some opaque algorithms and not allowing logins from it. From https://security.googleblog.com/2019/04/better-protection-ag...:

> Because we can’t differentiate between a legitimate sign in and a MITM attack on these platforms, we will be blocking sign-ins from embedded browser frameworks starting in June

Granted this was years ago, maybe the situation improved? I had to abandon my CEF project because of this.