I am trying to migrate some very old asp.net code to .net core, and there are many calls to a SOAP service.

I can add the connected service fine, but when I try and call it I always get the following response

***The HTTP request is unauthorized with client authentication scheme 'Anonymous'. 
The authentication header received from the server was 'Basic realm="gSOAP Web Service"'.***

When I try the same code from a test .net framework project it works fine.

Looking at the traffic via Fiddler, the .net core one is not setting the username and password at all from what I can tell. This is the Fiddler Auth header on the .net core call

No Proxy-Authorization Header is present.

Authorization Header is present: Basic Og==
Decoded Username:Password= :

Here is the code for the .net core version

    var lm = new ListManagerService.lmapiSoapClient();
    lm.ClientCredentials.UserName.UserName = "username";
    lm.ClientCredentials.UserName.Password = "password";
    Console.WriteLine("Current API Version: " + lm.ApiVersion());

and here is the same code that works fine on .net framework

  var lm = new lmapiSoap.lmapi();
  lm.Credentials = new System.Net.NetworkCredential("username", "password");
  Console.WriteLine("Current API Version: " + lm.ApiVersion());

and the header in Fiddler

No Proxy-Authorization Header is present.

Authorization Header is present: Basic dXNlcm5hbWU6cGFzc3dvcmQ=
Decoded Username:Password= username:password

Now I have found a work around, elsewhere on SO, where you can add a header manually, but that seems to be a lot of work as every call needs to be wrapped in a using statement like this

    using (new OperationContextScope(lm.InnerChannel))
    {
        // Add a HTTP Header to an outgoing request
        var auth = "Basic " + Convert.ToBase64String(System.Text.Encoding.Default.GetBytes(lm.ClientCredentials.UserName.UserName + ":" + lm.ClientCredentials.UserName.Password));
        var requestMessage = new HttpRequestMessageProperty();
        requestMessage.Headers["Authorization"] = auth;
        OperationContext.Current.OutgoingMessageProperties[HttpRequestMessageProperty.Name] = requestMessage;
        Console.WriteLine("Current API Version: " + lm.ApiVersion());
    }

But there must be an easier way - given how simple this was in all previous versions of .NET