Invalid Session – Auto Logout on IOS, Chrome, Safari, Firefox

I’m having a very annoying issue. I can’t stay logged in for more than 10 minutes. Most importantly, I can’t access the settings to deactivate my facebook. I keep getting “session expired”, “Your request could not be processed. Please try again” ANY TIME I click settings on IOS, Chrome, Safari or Firefox. Has anyone experienced this issue or know where to start for troubleshooting? I CANT DEACTIVATE FB.