Apple PushKit didUpdatePushCredentials is never called on iOS 9+ : <p>I am developing a VoIP app for iPhone. To receive calls, Apple developed PushKit so developers can send VoIP notifications using APNS.</p>

<p>Everything was working fine on iOS 8. When I updated to iOS 9, the <code>PKRegistryDelegate</code> does not fire the method <code>didUpdatePushCredentials</code> after registration.</p>

<p>Any ideas/suggestions?</p>
