Can't get EAAccessoryDidConnectNotification after connection

I can detect my MFI compliant chip in the list of Bluetooth devices (from my iphone 5C) but once the connection is established I do not get the notification EAAccessoryDidConnectNotification ... I use the demo EADemo proposed by Apple. Can you help me about that issue ?

I have also test it with showBluetoothAccessoryPickerWithNameFilter, and I get

BTM: connection to service 0x00000080 on device "BRAIN_WT12_2" 00:07:80:99:EE:4C succeeded.

So, why I don't get any EAAccessoryDidConnectNotification notifications?

Here is my code :

- (void)viewDidLoad {

[[EAAccessoryManager sharedAccessoryManager] showBluetoothAccessoryPickerWithNameFilter:nil completion:nil];

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(_accessoryDidConnect:) name:EAAccessoryDidConnectNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(_accessoryDidDisconnect:) name:EAAccessoryDidDisconnectNotification object:nil];
[[EAAccessoryManager sharedAccessoryManager] registerForLocalNotifications];

...