MP3 is playing only one time after countdown ends

Question

I have the following tool written for myself in .net Framework 4.8. It's a simple countdown and at zero a MP3-file is playing.

This is working, but only one time. If I restart the countdown, without closing the tool, than the MP3 is not playing anymore at zero, but the catch-Block is not triggert in PlaySound()-Method

Because it's a very tiny tool, I post the complete source code. I hope anyone could say me, why this error happens.

using System;
using System.Windows.Forms;
using NAudio.Wave;

namespace Kumpel_Counter
{
    public partial class Form1 : Form
    {
        private readonly Timer timer;
        private readonly IWavePlayer wavePlayer;
        private readonly AudioFileReader audioFile;

        private readonly TimeSpan originalTime = TimeSpan.Parse("00:30:00");
        private TimeSpan currentTime;
        private readonly TimeSpan interval = TimeSpan.FromSeconds(1);
        private bool isTimerRunning = false;

        public Form1()
        {
            InitializeComponent();
            currentTime = originalTime;

            timer = new Timer();
            timer.Interval = (int)interval.TotalMilliseconds;
            timer.Tick += timer1_Tick;

            try
            {
                wavePlayer = new WaveOut();
                audioFile = new AudioFileReader("sound.mp3");
                wavePlayer.Init(audioFile);
            } catch {
                MessageBox.Show("\"sound.mp3\" not found.");
            }
        }

        private void cmdStartStop_Click(object sender, EventArgs e)
        {
            if (!isTimerRunning)
            {
                if (TimeSpan.TryParseExact(txtSetTime.Text, @"hh\:mm\:ss", null, out currentTime))
                {
                    timer.Start();
                    isTimerRunning = true;
                    cmdStartStop.Text = "Stop";
                }
                else
                {
                    MessageBox.Show("Please use HH:mm:ss");
                }
            }
            else
            {
                ResetTimer();
            }
        }

        private void txtSetTime_TextChanged(object sender, EventArgs e)
        {
            if (txtSetTime.Text.Length > 8)
            {
                txtSetTime.Text = txtSetTime.Text.Substring(0, 8);
                txtSetTime.SelectionStart = txtSetTime.Text.Length;
            }
            else if (txtSetTime.Text.Length == 2 || txtSetTime.Text.Length == 5)
            {
                txtSetTime.Text += ":";
                txtSetTime.SelectionStart = txtSetTime.Text.Length;
            }
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            if (currentTime.TotalSeconds > 0)
            {
                currentTime = currentTime.Subtract(interval);
                txtSetTime.Text = currentTime.ToString(@"hh\:mm\:ss");
            }
            else
            {
                timer.Stop();
                isTimerRunning = false;
                cmdStartStop.Text = "Start";
                txtSetTime.Text = originalTime.ToString();
                PlaySound();
            }
        }

        private void cmdInfo_Click(object sender, EventArgs e)
        {
            MessageBox.Show(this, "Version: 1.0", "Info", MessageBoxButtons.OK, MessageBoxIcon.Information);
        }

        private void ResetTimer()
        {
            timer.Stop();
            currentTime = originalTime;
            txtSetTime.Text = currentTime.ToString(@"hh\:mm\:ss");
            isTimerRunning = false;
            cmdStartStop.Text = "Start";
        }

        private void PlaySound()
        {
            try
            {
                wavePlayer.Play();
            }
            catch (Exception ex)
            {
                MessageBox.Show($"Error playing MP3: {ex.Message}");
            }
        }
    }
}

I checked my code, but could not find the problem.