UDP activated sound is intermittent

I have a UDP activated routine which accepts a specific datagram packet and starts playing a 10-second long alert sound. Testing the code on a Toshiba Android TV (L5400) appears to be OK, a message is sent every 12 seconds. All hell broke loose when someone decided to randomly send a series of UDP packets at 5 - 8 seconds apart for stress testing.

After a while, the sound just simply disappears from the TV. If I turn off the random burst of UDP packets, the sound returns shortly. I am baffled because I have tried running the same code and test case on my Samsung Tab 4 tablet; using the tablet to emulate my Android TV, I discover absolutely no problems with the sound.

Does anybody have any idea as to why the sound might be disappearing on the Android TV?

I have attached parts of the code below.

private class ReceiveTask extends AsyncTask<Void, Void, Void> {
...
    while (bKeepRunning) {
        s.receive(p); //s is a DatagramSocket and p is a DatagramPacket
        message = new String(buffer, 0, p.getLength());
        lastMessage = message;
        runOnUiThread(updateTextMessage);
    }
...
}

private Runnable updateTextMessage = new Runnable() {
    public void run() {
    ...
        dosomething();
        playSound();
        dosomethingelse();
    ...
    }
};

private void playSound() {
    if(!isPlaying1){
        mp1 = new MediaPlayer();
        mp1 = MediaPlayer.create(context, R.raw.alert);
        mp1.start();
        isPlaying1 = true;
    }else{
        isPlaying1 = false;
        if(mp1.isPlaying()) {
            mp1.stop();
        }
        mp1.reset();
        mp1 = MediaPlayer.create(context, R.raw.alert);
        mp1.start();
        isPlaying1 = true;
    }
    mp1.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
        public void onCompletion(MediaPlayer mp1) {
            mp1.release();
            isPlaying1 = false;
        }
    });
}