Cookies are not saved when Webview2 is displayed using .show() method

My webview2 Control resides in a form and i am trying to show it from another form using ShowDialog() and Show().
The url I am displaying needs authentication and I want to skip the authentication when I load it second time. It wont ask for authentication during the second time, if I show the from using .ShowDialog() function. However if I use .Show() function , it is always ask for authentication. Cookies are not saved when it was displayed using .show() method. Can any one help me. Sample code is attached.

    public partial class StartForm : Form
    {
        public StartForm()
        {
            InitializeComponent();
        }

        private void LaunchModalWindowbutton_Click(object sender, EventArgs e)
        {
            WebForm webForm = new WebForm();
            webForm.ShowDialog();
        }

        private void LaunchNonModalWindowButton_Click(object sender, EventArgs e)
        {
            WebForm webForm = new WebForm();
            webForm.Show();
        }
    }


 public partial class WebForm : Form
    {
        private string m_url = "http://ottdev-cs.otxlab.net/CS/llisapi.dll/app/";
        public WebForm()
        {
            InitializeComponent();
            this.WindowState = FormWindowState.Maximized;
        }

        private async void webView_NavigationCompletedAsync(object sender, CoreWebView2NavigationCompletedEventArgs e)
        {
            var cookies = await webView.CoreWebView2.CookieManager.GetCookiesAsync(null);
            for (int i = 0; i < cookies.Count; i++)
            {
                Console.WriteLine("Cookie Name = {0} Value = {1}", cookies[i].Name, cookies[i].Value);
            }
        }


        private async void WebForm_LoadAsync(object sender, EventArgs e)
        {
            await webView.EnsureCoreWebView2Async();
            if (!string.IsNullOrWhiteSpace(m_url) && webView != null && webView.CoreWebView2 != null)
            {
                var cookies = await webView.CoreWebView2.CookieManager.GetCookiesAsync(null);
                for (int i = 0; i < cookies.Count; i++)
                {
                    Console.WriteLine("Cookie Name = {0} Value = {1}", cookies[i].Name, cookies[i].Value);
                }
                webView.CoreWebView2.Navigate(m_url);
            }
        }
    }
}

WebView2SampleApp.zip