iOS Device Rotation Instant Snap rather than anima

问题:

So I have an App where it is based on LandscapeRight LandscapeLeft.

The problem is that device rotations on my iPad and iPhone 5s instantly rotate with no animation. (iOS 9) On my older device iPhone4S (iOS 7) the animation flip occurs normally.

I've tested with a stripped down version of my project yet still can't work it out.

Here is how I setup my app stack:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    [super applicationDidFinishLaunching:application];

    self.navigationController = [[[UINavigationController alloc] init] autorelease];
    [self.window setRootViewController:self.navigationController];

    UIStoryboard * storyboard = [UIStoryboard storyboardWithName:@"Storyboard" bundle:nil];
    [self.navigationController pushViewController:[storyboard instantiateInitialViewController] animated:YES];

    [self.navigationController setNavigationBarHidden:YES];
 }

#ifdef __IPHONE_6_0
-(NSUInteger)application:(UIApplication *)application supportedInterfaceOrientationsForWindow:(UIWindow *)window {
    return UIInterfaceOrientationMaskLandscape;
}

- (NSUInteger)supportedInterfaceOrientations {
    return UIInterfaceOrientationMaskLandscape;
}
#endif

Any idea what could cause this? I don't have overloading functions for rotation commands, at least in my test view controllers and it is still happening.

Could this just be a new feature of iOS 9? If so where is the documentation? Any one have any recent post iOS 9.0 apps that rotate on the AppStore to link?