Not able to identify wrong username and password

My server is a spring boot application that uses spring security for handling authenticated conections.

The server responds with a 401 when bad credentials are sent, but the client is not able to show that to me, sending a generic error for my code.

I have looked to the code and saw this code on WebSocket.cs:

private void doHandshake ()
    {
      setClientStream ();
      var res = sendHandshakeRequest ();
      string msg;
      if (!checkHandshakeResponse (res, out msg))
        throw new WebSocketException (CloseStatusCode.ProtocolError, msg);

      if (_protocolsRequested)
        _protocol = res.Headers["Sec-WebSocket-Protocol"];

      if (_extensionsRequested)
        processSecWebSocketExtensionsServerHeader (res.Headers["Sec-WebSocket-Extensions"]);

      processCookies (res.Cookies);
    }

The 'res' variable has the information about bad credentials, but it nos used when throwing the WebSocketException. It is possible to add a new option to CloseStatusCode for bad credentials?

Start in WebSocket.cs at doHandshake, then trace sendHandshakeRequest and checkHandshakeResponse to see how the handshake response is represented before CloseStatusCode.ProtocolError is raised. Review the available CloseStatusCode values and the response information from the Spring Security server. Done means the client can distinguish bad credentials from the current generic handshake error.