Some sites keep cookies even when private windows close.
Open Firefox. Verify no cookies. Clear any cookies if they exist.
Then open a single private window.
Go to tripadvisor.com (happens with some other sites but only a few).
Browse a few pages.
Close the private Window. No private windows/Container tabs are open.
All tripadvisor cookies should be cleared but they are not.
Verified by Cookie Quick Manager.
Why and how does tripadvisor manage to keep cookies on my system.
In Private Mode, all data is stored in a temporary file. This file is removed when the browser is closed.
Cookie Quick Manager (firefox addon) show that under normal circumstances, when I open a private (or multiple private) window(s) and then visit sites, the cookies are created. When the last private window (or the only private window) is closed, all cookies associated with the private window(s) is/are removed - except from a few sites. While it may be true that they are all removed when I exit the browser, it appears they should be cleared when I exit private browsing.
My guess is that an add-on is causing this issue.
If you start in Firefox Safe Mode do you see this issue? If you don't see it in Firefox Safe Mode then it's probably an add-on or 3rd party software.
Is this about cookies or also possibly about storage ?
Is this also reported in the Firefox Cookie Manager ?
- Options/Preferences -> Privacy & Security
Cookies and Site Data: "Manage Data"