Conflicts between providers for the same email address 1. Conflicts between providers for the same email address If a user creates an account with an email/password and then tries to sign in with Google (same email), Firebase may generate an `auth/account-exists-with-different-credential` error. This forces the user to sign in using the original method and link the accounts manually. 2. Why Gmail in Brave is complicated to manage The privacy-focused Brave browser isolates profiles and blocks certain third-party cookies. Opening multiple Gmail accounts in different profiles can lead to session conflicts, redirection errors, or frequent re-authentication requests. 3. The impact on myactivity.google.com Every login to Gmail or a site using Google Sign-In generates a trace on *myactivity.google.com*. If you open multiple profiles or frequently switch accounts, this multiplies the entries, making the history difficult to track and manage.