I'm currently trying implement Facebook login using the 4.0 version of the SDK, this also happens with the 3.+ version. When I call logInWithReadPermissions (4.0 version) or openActiveSessionWithReadPermissions (3.+ version). The closure/block is called immediately with isCancelled (4.0 version) and ClosedFailedLogin (3.+ version) before the user can make a selection (cancel or ok). I thought it may be a problem with the URL Scheme in my plist settings but I've checked it over and over and everything seems to be right. Just wondering if anyone may have any ideas on solving this problem. My Bundle ID is right, single signin is on, native app is enabled, in the Facebook dev console. See some sample code and configurations below (4.0 version).
I had the some problem but I found a workaround. You can set the login behaviour of the Login Manager to use the Facebook details on the phone. The default behaviour is FBSDKLoginBehaviorSystemNative and that tries to use the Facebook app first and then if its not there, it uses a web modal.
Instead of doing it that way and passing around urls that don't seem to work you can set the login behaviour as FBSDKLoginBehaviorSystemAccount.
Long story short, try:
let fbLoginManager = FBSDLoginManager(); fbLoginManager.loginBehavior = FBSDKLoginBehaviorSystemAccount; // call login method of choice here