Yesterday both my devices (iPad Pro and iPhone 7) both started repeatedly presenting pop ups asking me to re-enter my Facebook password in Settings. If I go to Settings I can enter my password and it validates ok, but a few mins later the same pop up reappears, if I go back to Settings it says 'there was a problem accessing your account' and I have to enter it again. I can't get out of this loop! I've tried restarting Facebook, restarting Settings, rebooting the device, deleting the account and signing back in, even deleting the whole Facebook app and reinstalling. Nothing's fixes it. The weird thing is I can delete the account and Facebook still seems to work just fine! Any ideas what's going on and how to resolve it?