Application is not resuming if started from NFC tag

Question

I have an application NFC capable. If I don't start it from NFC tag it resumes normaly even from notification bar, even by long pressing home button. The problem is when I start the application with the NFC tag. When I try to resume, it restarts the application. Any suggestions?

This is my launcher activity in the manifest file

<activity
        android:name=".hmi.DebugPreferenceActivity"
        android:label="@string/app_name"
        android:theme="@style/AppTheme"
        android:launchMode="singleInstance">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
        <intent-filter>
             <action android:name="android.nfc.action.TECH_DISCOVERED" />
         </intent-filter>

         <meta-data
             android:name="android.nfc.action.TECH_DISCOVERED"
             android:resource="@xml/filter_nfc" />

         <intent-filter>
             <action android:name="android.nfc.action.TAG_DISCOVERED" />

             <category android:name="android.intent.category.DEFAULT" />
         </intent-filter>

    </activity>

This is where I create my notification.

private void createNotification() {

Intent notificationIntent = new Intent(mContext, DebugPreferenceActivity.class);
    notificationIntent.setAction(Intent.ACTION_MAIN);
    notificationIntent.addCategory(Intent.CATEGORY_LAUNCHER);

    PendingIntent pendingIntent = PendingIntent.getActivity(mContext, 0,
            notificationIntent, 0);


    NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(
            this)
            .setSmallIcon(R.drawable.app_icon)
            .setContentTitle(
                    mContext.getResources().getString(R.string.app_name))
            .setContentIntent(pendingIntent).setContentText(null);
    mNotificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
    mBuilder.setOngoing(true);
    mNotificationManager.notify(0, mBuilder.build());

}