Using an MVC API with Windows Authentication from VBA - asp.net-mvc

Question

I have developed a MVC Application, which, for the purpose of this question only has one controller:
Public Function GetValue()
Return User.Identity.Name
End Function
The application is to be used on an Intranet network, therefore, I have set it to 'Windows Authentication'
The aim is to query this application, through VBA.
Set objHTTP = CreateObject("MSXML2.ServerXMLHTTP")
With objHTTP
.Open "GET", URL, False
.setRequestHeader "User-Agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)"
.setRequestHeader "Content-type", "application/json"
.setRequestHeader "data-type", "json"
.send
.WaitForResponse
sResult = .ResponseText
End With
Debug.Print (sResult)
If I run the application locally (ie. debug on the computer that is running Excel), it works through Chrome (accessing localhost:xxxxx/api/name returns an xml file with my ActiveDirectory username).
The VBA routine works fine as well, and the Output window displays the XML I get in Chrome.
Now, if I publish the project to the IIS server, it still works through Chrome (accessing myserver/api/name returns an xml file with my ActiveDirectory username).
However, when I run the VBA module, it returns an Error 401:
Error:401 - Unauthorized: Access is denied due to invalid credentials.
The fact that it works in browsers leads me to believe that server-side configuration is OK, and that I need to tweak something in my VBA.
I have to admit that I am a bit clueless at this point...
Thank you for any leads you may give me :)

Answer 1

Thanks to #SWa comment, I solved this with a minor tweak to the function: Switching to WinHttpRequest and using setAutoLogonPolicy 0
Set objHTTP = CreateObject("WinHttp.WinHttpRequest.5.1")
With objHTTP
.Open "GET", URL, False
.setRequestHeader "User-Agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)"
.setRequestHeader "Content-type", "application/json"
.setRequestHeader "data-type", "json"
.setAutoLogonPolicy 0
.send
.WaitForResponse
sResult = .ResponseText
End With
Debug.Print (sResult)