Using SSIS script to connect to API Fails

Question

I'm using SSIS (Visual Studio 2015 targeting SQL Server 2016) to build a script task to consume an API. I built the following code on my local machine (Visual Studio 2017) and it works great:

    public void Main()
    {
        string baseURL = "API.com";

        Uri requestUri = new Uri(baseURL);
        HttpWebRequest req = WebRequest.Create(requestUri) as HttpWebRequest;

        string username = "APIKEY";
        string password = "";
        string auth64 = Convert.ToBase64String(System.Text.ASCIIEncoding.ASCII.GetBytes(username + ":" + password));
        //ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls |SecurityProtocolType.Tls11 |
        //SecurityProtocolType.Tls12;
        //ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls | SecurityProtocolType.Tls11 |
       // SecurityProtocolType.Tls12|SecurityProtocolType.Ssl3;

        ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;
        //System.Net.ServicePointManager.SecurityProtocol |= SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12;

        //ServicePointManager.SecurityProtocol = (SecurityProtocolType)768 | (SecurityProtocolType)3072;

        //System.Net.ServicePointManager.SecurityProtocol = (System.Net.SecurityProtocolType)3072;
        //System.Net.ServicePointManager.SecurityProtocol = (SecurityProtocolType)0x00000C00;
        req.Headers.Add("Authorization", "Basic " + auth64);
        //req.KeepAlive = false;
        //req.ProtocolVersion = HttpVersion.Version10;
        //req.ServicePoint.ConnectionLimit = 1;

        try
        {
            using (HttpWebResponse response = (HttpWebResponse)req.GetResponse())
            {
                using (StreamReader sr = new StreamReader(response.GetResponseStream()))
                {
                    Console.WriteLine("Worked");
                }
            }
        }
        catch (Exception e)
        {
            Console.WriteLine("Didn't Work");
        }
    }

As soon as I paste this into a script task and try to run it I get the following error:

Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host

Digging around a little more I see this:

The underlying connection was closed: an unexpected error occurred on send

Everything on this error that I can find suggests changing the SerivcePointManager to TLS12. Please note all of the iterations that have been commented out in the above code. Nothing seems to work.