The feature of staying signed in uses a "persistent" cookie, meaning a cookies whose expiration date is in the future and it does not expire at the end of the current session. There are a number of ways that a cookie might be lost between sessions, including: * Using a private window for Google/Gmail * Setting Firefox to allow only session cookies ( without making an exception for Google ) * Setting Firefox to clear history when it closes and selected Cookies as one of the categories to clear ( this feature does not honor exceptions ) * Using an extension that cleans up cookies * Using external software that cleans up browser data Do you recall customizing any privacy, history, or cookie settings on the Options page? You can check that here: * Windows: "3-bar" menu button (or Tools menu) > Options * Mac: "3-bar" menu button (or Firefox menu) > Preferences * Linux: "3-bar" menu button (or Edit menu) > Preferences * Any system: type or paste '''about:preferences''' into the address bar and press Enter/Return to load it In the left column, click '''Privacy & Security''' On the right side, in the '''History''' section, you can verify: * Firefox will: Remember history => Good * Firefox will: Never remember history => FLUSHES COOKIES * Firefox will: Use custom settings for history => check for:<br><br>"Clear history when Firefox closes" is either: ** Not checked (not turned on) ** Checked (turned on) but when you click the Settings button on the right, Cookies are not checked (not set to be cleared) On the right side, in the '''Cookies and Site Data''' section, can you verify: "Accept cookies and site data from websites (recommended)" is selected and either: * "Keep until" is set to They expire, or * "Keep until" is set to Firefox closes AND when you click the Exceptions button, https://google.com is set to ALLOW Does all that check out?