Does not work with IISExpress #2

Doesn't work with IISExpress, only web:

SocketException: An existing connection was forcibly closed by the remote host.

IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.
System.Net.Sockets.NetworkStream.EndRead(IAsyncResult asyncResult)

WebException: The underlying connection was closed: An unexpected error occurred on a receive.
System.Net.HttpWebRequest.EndGetResponse(IAsyncResult asyncResult)

HttpRequestException: An error occurred while sending the request.
System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)