A notificação setAutoCancel (true) não funciona se clicar em Ação

Eu tenho uma notificação com uma ação dentro dela. Quando toco na notificação, ela é removida da lista. No entanto, quando clico na ação, ela conclui com êxito a ação (ou seja, faz uma chamada), mas quando volto à lista de notificações, ela permanece lá. Código relativo do AlarmReceiver:

public class AlarmReceiver extends BroadcastReceiver {
Meeting meeting;

/**
 * Handle received notifications about meetings that are going to start
 */
@Override
public void onReceive(Context context, Intent intent) {

    // Get extras from the notification intent
    Bundle extras = intent.getExtras();
    this.meeting = extras.getParcelable("MeetingParcel");

    // build notification pending intent to go to the details page when click on the body of the notification
    Intent notificationIntent = new Intent(context, MeetingDetails.class);
    notificationIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    notificationIntent.putExtra("MeetingParcel", meeting);      // send meeting that we received to the MeetingDetails class
    notificationIntent.putExtra("notificationIntent", true);    // flag to know where the details screen is opening from

    PendingIntent pIntent = PendingIntent.getActivity(context, 0, notificationIntent, 0);

    // build intents for the call now button
    Intent phoneCall = Call._callIntent(meeting);
    if (phoneCall != null) {

        PendingIntent phoneCallIntent = PendingIntent.getActivity(context, 0, phoneCall, PendingIntent.FLAG_CANCEL_CURRENT);

        int flags = Notification.FLAG_AUTO_CANCEL;

        // build notification object
        NotificationCompat.Builder builder = new NotificationCompat.Builder(context);
        Notification notification = builder.setContentTitle("Call In")
                .setContentText(intent.getStringExtra("contextText"))
                .setTicker("Call In Notification")
                .setColor(ContextCompat.getColor(context, R.color.colorBluePrimary))
                .setAutoCancel(true)                    // will remove notification from the status bar once is clicked
                .setDefaults(Notification.DEFAULT_ALL)  // Default vibration, default sound, default LED: requires VIBRATE permission
                .setSmallIcon(R.drawable.icon_notifications)
                .setStyle(new NotificationCompat.BigTextStyle()
                        .bigText(meeting.description))
                .addAction(R.drawable.icon_device, "Call Now", phoneCallIntent)
                .setCategory(Notification.CATEGORY_EVENT)   // handle notification as a calendar event
                .setPriority(Notification.PRIORITY_HIGH)    // this will show the notification floating. Priority is high because it is a time sensitive notification
                .setContentIntent(pIntent).build();

        notification.flags = flags;

        // tell the notification manager to notify the user with our custom notification
        NotificationManager notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
        notificationManager.notify(0, notification);
    }
  }
}