Timern på min windows forms vill inte stoppa.

Timern på Winner funktionen vägrar att sluta ticka även om jag använder timer1.Stop(); 

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Windows_forms
{
  public partial class Form1 : Form
  {
    int score;
    double timer = 0;


  public Form1()
  {
    InitializeComponent();
  }

  private void Form1_Load(object sender, EventArgs e)
  {
  }

 

  private void Start_btn_Click(object sender, EventArgs e)
  {
    Random_location_btn.Visible = true;

    Point Btn_position = Location_randomizer();
    Start_btn.Visible = false;

    Random_location_btn.Location = Btn_position;
    timer1.Start();


  }


  public Point Location_randomizer()
  {
    int location_x;
    int location_y;

    Random rand = new Random();

    location_x = rand.Next(0, 890);
    location_y = rand.Next(0, 890);
    Point position = new Point(location_x, location_y);
    return (position);
  }

  private void Score_Label_Click(object sender, EventArgs e)
  {

  }

  private void Random_location_btn_Click(object sender, EventArgs e)
  {
    score++;
    Score_Label.Text = "score:" + " " + score;
    Point btn_position = Location_randomizer();

    Random_location_btn.Location = btn_position;

  }

  private void timer1_Tick(object sender, EventArgs e)
  {
    timer += 0.1;
    Time_label.Text = "Time:" + " " + timer;

    Winner();
  }

  private void Winner()
  {
    if (timer < 10 && score == 10)
    {
      MessageBox.Show("You won!");
      timer1.Stop();
      Random_location_btn.Enabled = false;
      timer = 0;
      score = 0;
    }
    else if (timer >= 10)
    {
      MessageBox.Show("You lost :(");
      timer1.Stop();

      Random_location_btn.Enabled = false;
      timer = 0;
    }
  
  }

  private void newGameToolStripMenuItem_Click(object sender, EventArgs e)
  {
    timer = 0;
    timer1.Stop();
    Time_label.Text = "Time: " + " 0";
    Start_btn.Visible = true;
    Random_location_btn.Visible = false;
  }
}