SendGrid hanging only in web app (not in console app)

Question

So i have a bit of a weird things going on. I'm trying to get SendGrid v9 working on my web app. I've run this through a bunch of test, including creating a console app to test. It works great in the console app but hangs in the web app. I'm obviously missing something - possibly to do with the async call, but really looking for an assist:

My console app:

namespace Example
{
    using System;
    using System.Threading.Tasks;
    using Newtonsoft.Json;
    using SendGrid;
    using SendGrid.Helpers.Mail;
    using System.Collections.Generic;
    using System.Diagnostics;

    internal class Example
    {
        private static void Main()
        {
            Execute().Wait();
        }

        static async Task Execute()
        {
            var client = new SendGridClient("[MYKEY]");

            // Send a Single Email using the Mail Helper
            var from = new EmailAddress("my@email.com", "Example User");
            var subject = "Hello World from the SendGrid CSharp Library Helper!";
            var to = new EmailAddress("my@email.com", "Example User");
            var plainTextContent = "Hello, Email from the helper [SendSingleEmailAsync]!";
            var htmlContent = "<strong>Hello, Email from the helper! [SendSingleEmailAsync]</strong>";
            var msg = MailHelper.CreateSingleEmail(from, to, subject, plainTextContent, htmlContent);

            var response = await client.SendEmailAsync(msg);
            Debug.WriteLine(msg.Serialize());
            Debug.WriteLine(response.StatusCode);
            Debug.WriteLine(response.Headers);
        }
    }
}

My web app:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Diagnostics;
using System.Threading.Tasks;
using Newtonsoft.Json;
using SendGrid;
using SendGrid.Helpers.Mail;


namespace WebAppTest
{
    public partial class WebForm1 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            Execute().Wait();
        }

        public static async Task Execute()
        {
            var client = new SendGridClient("[MYKEY]");

            // Send a Single Email using the Mail Helper
            var from = new EmailAddress("my@email.com", "Example User");
            var subject = "Hello World from the SendGrid CSharp Library Helper!";
            var to = new EmailAddress("my@email.com", "Example User");
            var plainTextContent = "Hello, Email from the helper [SendSingleEmailAsync]!";
            var htmlContent = "<strong>Hello, Email from the helper! [SendSingleEmailAsync]</strong>";
            var msg = MailHelper.CreateSingleEmail(from, to, subject, plainTextContent, htmlContent);

            var response = await client.SendEmailAsync(msg); //It hangs on this call

            Debug.WriteLine(msg.Serialize());
            Debug.WriteLine(response.StatusCode);
            Debug.WriteLine(response.Headers);
        }
    }
}

These are blank project, nothing much in the web.cofigs or app.configs

What am i missing. Why is the web app not functioning with this but the console app does?

TIA