Why does the value of DateTimePicker change after minimizing the form?

Question

I have a WinForms-based (.NET Framework 4.7.2) form that flickers when displayed because it has a lot of controls. I turned on DoubleBuffred and overridden CreateParams. Although it seemed to stop flickering, it would flicker again after minimizing and opening again, so I overridden OnResize and used RecreateHandle() when FormWindowState.Normal. This does solve the flickering problem, but I found that when I minimized the form and then restored it, the default value of DateTimePicker changed. And other controls such as CheckBox are normal. Why is this?

The relevant code is as follows:

private void FormSettings_Load(object sender, EventArgs e)
{
    DateTimePickerMain.Value = ConfigManager.IsValidData(SelectedTime) ? SelectedTime : DateTime.Now;
    // MessageBox.Show($"{SelectedTime}");
    // At first I thought SelectedTime was invalid, then I checked it using MessageBox and found that
    // it was indeed a valid date, but the DateTimePicker displayed the current date.
}

protected override CreateParams CreateParams
{
    get
    {
        CreateParams cp = base.CreateParams;
        cp.ExStyle |= 0x02000000;
        return cp;
    }
}

protected override void OnResize(EventArgs e)
{
    base.OnResize(e);

    if (WindowState == FormWindowState.Normal)
    {
        RecreateHandle();
        Activate();
    }
}

More importantly, even if I use DateTimePickerMain.Value = new DateTime(2024, 1, 1) directly, it will display the current date after minimizing.