Sending post does not work on server

Question

I am attempting to get the silly name maker to work using a webhook hosted on my server. Using PTs-V2 I am able to see the JSON post from Dialogflow.

...{"color":"red","number":6}...

Using Hurl.it I am able to successfully send the post to my server and get the correct response.

{ "speech": "Alright, your silly name is red 6! I hope you like it. See you next time."...

But when I try to use my own server for Dialogflow it does not work. Not sure if there is something I'm missing.

Webhook on server

'use strict';

const https = require('https');
const fs = require('fs');

var privatekey = fs.readFileSync('...');
var certificate = fs.readFileSync('...');
var credentials = {key: privatekey, cert: certificate};

process.env.DEBUG = 'actions-on-google:*';
var DialogflowApp = require('actions-on-google').DialogflowApp;
const express = require('express');
const bodyParser = require('body-parser');

let app = express();
app.use(bodyParser.json({type: 'application/json'}));
var httpsServer = https.createServer(credentials, app);
httpsServer.listen(443);

const NAME_ACTION = 'make_name';
const COLOR_ARGUMENT = 'color';
const NUMBER_ARGUMENT = 'number';

app.get('/', function(req, resp) {
 resp.send("Hello!");
 console.log('app.get');
});

app.post('/', function (request, response){
 console.log('app.post');
 const app = new DialogflowApp({request: request, response: response});

  console.log('Request headers: ' + JSON.stringify(request.headers));
  console.log('Request body: ' + JSON.stringify(request.body));

  // Make a silly name
  function makeName (app) {
    let number = app.getArgument(NUMBER_ARGUMENT);
    let color = app.getArgument(COLOR_ARGUMENT);
    app.tell('Alright, your silly name is ' +
      color + ' ' + number +
      '! I hope you like it. See you next time.');
  }

  let actionMap = new Map();
  actionMap.set(NAME_ACTION, makeName);

  app.handleRequest(actionMap);
});

Thanks for any help.

Edit: Response from Dialogflow when I am running Apache server for website on port

"status": { "code": 206, "errorType": "partial_content", "errorDetails": "Webhook call failed. Error: Failed to parse webhook JSON response: java.lang.IllegalStateException: Expected BEGIN_OBJECT but was STRING at line 1 column 1 path $.", "webhookTimedOut": false },

Response when the JS server is running on the port and not Apache

"status": { "code": 206, "errorType": "partial_content", "errorDetails": "Webhook call failed. Error: Webhook response was empty.", "webhookTimedOut": false },

Dialogflow Setup (screenshots)

• Fulfillment
• Intent that calls webhook
• Result when Apache webserver is running
• Result when JS webhook is running

My JS server never receives a post.