Winform C# events not working after applying MetroFramework UI

Question

I installed MetroFramework in my project, but events are not working.

namespace WindowsFormsApp1
{
    public partial class Form1 : MetroFramework.Forms.MetroForm
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            this.Text = "Test";
        }


        private void Form1_Click(object sender, EventArgs e)
        {
            this.BackColor = Color.Blue;
            this.Text = "click";
        }
    }
}

this is my Form1.cs file, and Form1_Click function working randomly. (Click event) Form1_Load function is working. the application title is 'Test'.

when I change code MetroFramework.Form.MetroForm to 'Form', It works well.

.Net version = 4.7.2 MetroFramework version = 1.2.0.3

when i click the form window, change the window backColor and Text