NSStream for swift works on simulator but not iphone

Question

This code works on the simulator, but not on my iphone with ios 10.3.1. It is connecting to a python client.

//
//  ViewController.swift
//  1st robot app
//
//  Created by Tristan Chandraratna on 13/2/17.
//  Copyright © 2017 Tristan Chandraratna. All rights reserved.
//

import UIKit

class ViewController: UIViewController, StreamDelegate {

    //Button
    var buttonConnect : UIButton!


    //Label
    var label : UILabel!
    var labelConnection : UILabel!


    //Socket server
    let addr = "192.168.0.14"
    let port = 9876

    //Network variables
    var inStream: InputStream?
    var outStream: OutputStream?

    //Data received
    var buffer = [UInt8](repeating: 0, count: 200)

    override func viewDidLoad() {
        super.viewDidLoad()

        ButtonSetup()

        LabelSetup()
    }

    //Button Functions
    func ButtonSetup() {
        buttonConnect = UIButton(frame: CGRect(x: 20, y: 50, width: 300, height: 30))
        buttonConnect.setTitle("Connect to server", for: UIControlState())
        buttonConnect.setTitleColor(UIColor.blue, for: UIControlState())
        buttonConnect.setTitleColor(UIColor.cyan, for: UIControlState.highlighted)
        buttonConnect.addTarget(self, action: #selector(ViewController.btnConnectPressed(_:)), for: UIControlEvents.touchUpInside)
        view.addSubview(buttonConnect)

        let buttoniPhone = UIButton(frame: CGRect(x: 20, y: 100, width: 300, height: 30))
        buttoniPhone.setTitle("Send \"This is iPhone\"", for: UIControlState())
        buttoniPhone.setTitleColor(UIColor.blue, for: UIControlState())
        buttoniPhone.setTitleColor(UIColor.cyan, for: UIControlState.highlighted)
        buttoniPhone.addTarget(self, action: #selector(ViewController.btniPhonePressed(_:)), for: UIControlEvents.touchUpInside)
        view.addSubview(buttoniPhone)

        let buttonQuit = UIButton(frame: CGRect(x: 20, y: 150, width: 300, height: 30))
        buttonQuit.setTitle("Send \"Quit\"", for: UIControlState())
        buttonQuit.setTitleColor(UIColor.blue, for: UIControlState())
        buttonQuit.setTitleColor(UIColor.cyan, for: UIControlState.highlighted)
        buttonQuit.addTarget(self, action: #selector(ViewController.btnQuitPressed(_:)), for: UIControlEvents.touchUpInside)
        view.addSubview(buttonQuit)

        let LWslide = UISlider(frame: CGRect(x:0,y:0,width:50,height:300))
        LWslide.maximumValue = Float(1023)
        LWslide.minimumValue = Float(-1023)
        LWslide.value = Float(0)
    }

    func btnConnectPressed(_ sender: UIButton) {
        NetworkEnable()

        buttonConnect.alpha = 0.3
        buttonConnect.isEnabled = false
        buttonConnect.setTitleColor(UIColor.blue, for: UIControlState())
    }
    func btniPhonePressed(_ sender: UIButton) {
        print("sending")
        let data : Data = "This is iPhone".data(using: String.Encoding.utf8)!
        outStream?.write((data as NSData).bytes.bindMemory(to: UInt8.self, capacity: data.count), maxLength: data.count)
        print("sent")
    }
    func btnQuitPressed(_ sender: UIButton) {
        let data : Data = "Quit".data(using: String.Encoding.utf8)!
        outStream?.write((data as NSData).bytes.bindMemory(to: UInt8.self, capacity: data.count), maxLength: data.count)
    }
    //Label setup function
    func LabelSetup() {
        label = UILabel(frame: CGRect(x: 0,y: 0,width: 300,height: 150))
        label.center = CGPoint(x: view.center.x, y: view.center.y+100)
        label.textAlignment = NSTextAlignment.center
        label.numberOfLines = 0 //Multi-lines
        label.font = UIFont(name: "Helvetica-Bold", size: 20)
        view.addSubview(label)

        labelConnection = UILabel(frame: CGRect(x: 0,y: 0,width: 300,height: 30))
        labelConnection.center = view.center
        labelConnection.textAlignment = NSTextAlignment.center
        labelConnection.text = "Please connect to server"
        view.addSubview(labelConnection)
    }

    //Network functions
    func NetworkEnable() {
        print(addr)
        print("NetworkEnable")
        Stream.getStreamsToHost(withName: addr, port: port, inputStream: &inStream, outputStream: &outStream)
        if inStream != nil && outStream != nil{
            inStream!.delegate = self
            outStream!.delegate = self

            inStream!.schedule(in: RunLoop.current, forMode: RunLoopMode.defaultRunLoopMode)
            outStream!.schedule(in: RunLoop.current, forMode: RunLoopMode.defaultRunLoopMode)

            inStream!.open()
            outStream!.open()
        }
        buffer = [UInt8](repeating: 0, count: 200)
        let data : Data = "iPhone connected".data(using: String.Encoding.utf8)!
        print((data as NSData).bytes.bindMemory(to: UInt8.self, capacity: data.count))
        outStream?.write((data as NSData).bytes.bindMemory(to: UInt8.self, capacity: data.count), maxLength: data.count)
        print("NetworkEnabled")
    }

    func stream(_ aStream: Stream, handle eventCode: Stream.Event) {

        switch eventCode {
        case Stream.Event.endEncountered:
            print("EndEncountered")
            labelConnection.text = "Connection stopped by server"
            inStream?.close()
            inStream?.remove(from: RunLoop.current, forMode: RunLoopMode.defaultRunLoopMode)
            outStream?.close()
            print("Stop outStream currentRunLoop")
            outStream?.remove(from: RunLoop.current, forMode: RunLoopMode.defaultRunLoopMode)
            buttonConnect.alpha = 1
            buttonConnect.isEnabled = true
        case Stream.Event.errorOccurred:
            print("ErrorOccurred")

            inStream?.close()
            inStream?.remove(from: RunLoop.current, forMode: RunLoopMode.defaultRunLoopMode)
            outStream?.close()
            outStream?.remove(from: RunLoop.current, forMode: RunLoopMode.defaultRunLoopMode)
            labelConnection.text = "Failed to connect to server"
            buttonConnect.alpha = 1
            buttonConnect.isEnabled = true
            label.text = ""
        case Stream.Event.hasBytesAvailable:
            print("HasBytesAvailable")

            if aStream == inStream {
                inStream!.read(&buffer, maxLength: buffer.count)
                let bufferStr = NSString(bytes: &buffer, length: buffer.count, encoding: String.Encoding.utf8.rawValue)
                label.text = bufferStr! as String
                print(bufferStr!)
            }

        case Stream.Event.hasSpaceAvailable:
            print("HasSpaceAvailable")
        case Stream.Event():
            print("None")
        case Stream.Event.openCompleted:
            print("OpenCompleted")
            labelConnection.text = "Connected to server"
        default:
            print("Unknown")
        }
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }

}