My father uses Linux Mint 22.3 and Firefox, both kept up to date. For the past couple of months, Firefox has been forgetting his Google and Gmail login session. Every visit—or sometimes even after only 20 minutes—requires entering his password and completing 2FA again.
Firefox is not set to block cookies, and the browser's site-data list does not show cookies for Gmail or other Google services. I have tried clearing existing data, restoring Firefox's default settings, and reinstalling it, but the problem continues. His mother uses another account on the same computer without any login problems, and other Linux computers on the same network also work normally.
The issue began around the time he got a new phone running GrapheneOS, although Google works normally on the phone. What could cause Firefox to discard or fail to save Google's login session, and what should I check next?
3 Answers
The Firefox and Mint versions are worth confirming first, but since Firefox has been updated throughout the problem, this probably is not simply an outdated browser issue. The fact that another user account on the same computer works suggests checking this user’s Firefox profile, privacy settings, extensions, and any per-site settings rather than the network or the computer as a whole.
A shared network issue such as CGNAT could sometimes trigger extra verification, especially if Google sees changing or suspicious IP addresses, but it would not normally explain Firefox failing to retain site data for only one account. Since other users and machines on the same connection are unaffected, the local Firefox profile is the more likely place to investigate. Also check whether the system clock is accurate, since incorrect time can invalidate login sessions.
Google login state depends on saved site data and session tokens, not just a cookie visibly labeled for Gmail. If Firefox is configured to delete cookies or site data when closed, is using strict tracking protection, or has an extension clearing Google data, the session can disappear. Check Firefox Settings under Privacy & Security, review the cookie and site-data exceptions, temporarily disable privacy extensions, and test with a fresh Firefox profile. If a clean profile stays logged in, the existing profile configuration or an extension is responsible.
Mint is 22.3, and Firefox has been kept current. I’ll focus on the affected user profile and its site-specific settings.