This cannot be stressed enough. If you log into Facebook on a public computer (library, hotel business center, university lab), uncheck the "Keep me logged in" box. After you finish, click your profile picture > "Log Out" explicitly. Closing the browser is not enough.
For most users, logging into Facebook on a desktop is straightforward: facebook login desktop
Pro tip: Check the "Keep me logged in" box only if you are on a personal, private computer. Never check this on a public or shared device. This cannot be stressed enough
Facebook allows you to see every device currently logged into your account. To review: Pro tip: Check the "Keep me logged in"
On the login screen, you will see a check box labeled "Keep me logged in."
You try to log into business.facebook.com but get redirected to the main Facebook login, then back again.