See Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems. Some extensions can cause problems with logging in to websites, especially extensions associated with certain websites. To learn more about clearing cookies, site data and cached web content in Firefox, see Clear cookies and site data in Firefox. Make sure other items you want to keep are not selected.
The last update was released in 2018 and after a long gap, Facebook is pushing out a new update.
Once you've joined the beta program, learn how to get started as a. If you don't have Facebook installed already, tap Download Facebook on Google Play. If you changed any settings, try logging in to the site again. Complete the following steps from your Android device to access and test the beta version of Facebook for Android: Go to the Google Play Store and log in if necessary. For instructions, see Websites say cookies are blocked - Unblock them.Make sure that cookies are enabled for the site in question.
5 Security application is blocking cookies.