Apparently it's a feature where you can't update your security question either: We want to make sure that your account and the information in it stays safe, so

Apparently it's a feature where you can't update your security question either: We want to make sure that your account and the information in it stays safe, so once you set up a security question on your account there’s no way to update it. Sorry for the inconvenience. https://www.facebook.com/help/?page=227159377299846 https://www.facebook.com/help/?page=227159377299846