Qt5 (5.7) Websockets do not work on Windows Phone - c++

Question

Hello dear fellow programmers,
we try to write an application that will run on windows phone and android.
Part of this app ist to establish a secure connection to a websocket server, which does not work on the windows phone. Works however perfect under Linux.
//constructor opening connection
MeteorDDP::MeteorDDP(QString uri){
QUrl wsUri = QUrl("wss://"+uri+"/websocket");
qDebug()<<wsUri;
connect(&wsClient, &QWebSocket::textMessageReceived,this, &MeteorDDP::handleMessage);
connect(&wsClient, &QWebSocket::connected,this, &MeteorDDP::onConnected);
connect(&wsClient, &QWebSocket::stateChanged, this, &MeteorDDP::onStateChanged);
connect(&wsClient, static_cast<void(QWebSocket::*)(QAbstractSocket::SocketError)>(&QWebSocket::error),
[=](QAbstractSocket::SocketError error){
qDebug()<<error<<"error";
});
connect(&wsClient, &QWebSocket::sslErrors, this, &MeteorDDP::onSslError);
wsClient.open(wsUri);
wsClient.flush();
}
And a method which just should output connected:
void MeteorDDP::onConnected(){
qDebug()<<"connected";
}
H file:
#ifndef METEORDDP_H
#define METEORDDP_H
#include <QString>
#include <QHash>
#include <QUrl>
#include <QtWebSockets/QtWebSockets>
class MeteorDDP : public QObject
{
Q_OBJECT
public:
MeteorDDP(QString server);
protected:
QWebSocket wsClient;
void onConnected();
void onStateChanged(QAbstractSocket::SocketState state);
void onSslError(void);
void onError(QAbstractSocket::SocketError error);
}
Methods:
void MeteorDDP::onStateChanged(QAbstractSocket::SocketState state){
qDebug() <<state<<"state Changed";
}
void MeteorDDP::onError(QAbstractSocket::SocketError error){
qDebug()<<error <<"error";
}
void MeteorDDP::onSslError(){
qDebug() <<"ssl error";
}