Problem with connecting multiple MFI controllers

Hi!

I'm currently working on a game in which I'm trying to allow multiplayer, with multiple MFI controllers. I am testing on an iPhone 6, running iOS 8.3, and 2 Madcatz C.T.R.L. controllers. I have been able to verify, using the app "Game Controller Tester" by Chibata Creations, that both controllers are indeed connected to the device. However, when I call "[GCControllers controllers]" in my app, the array returned has only one GCController object (determined both using a breakpoint and an NSLog). I have posted the relevant code (in Objective C) below, and hope someone may have encountered and solved a similar error, or be able to give me some pointers.

In AppDelegate.m

Code:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Override point for customization after application launch.
    
    if ([GCController class])
    {
        NSNotificationCenter* center = [NSNotificationCenter defaultCenter];
        
        [center addObserver:self.window.rootViewController selector:@selector(setUpControllers:) name:GCControllerDidConnectNotification object:nil];
        
        [center addObserver:self.window.rootViewController selector:@selector(setUpControllers:) name:GCControllerDidDisconnectNotification object:nil];
        
        [GCController startWirelessControllerDiscoveryWithCompletionHandler:nil];
    }
    
    return YES;
}

In a view controller:

Code:

-(void)setUpControllers:(NSNotification*)notification
{
    NSArray* potentialControllers = [GCController controllers];//this is the array that has only 1 element, but should have 2

    self.controllers = [[NSMutableArray alloc] init];
    
    if ([potentialControllers count] >= 1)
    {
...
    }
}

Thanks very much for your time!