QWebEngineView becomes all black when calling winId

TestWebView::TestWebView(QWidget *parent) : QWidget(parent)
{
    QWebEngineView* w = new QWebEngineView(this);
    w->setUrl(QUrl("http://www.bing.com"));

    QPushButton* ptr_one = new QPushButton(this);
    ptr_one->setFixedSize(30, 30);
    connect(ptr_one, &QPushButton::clicked, this, [=]() {
        if (this->isFullScreen())
        {
            this->showNormal();
        }
        else
        {
            this->showFullScreen();
        }
    });

    QHBoxLayout* ptr_top_layout = new QHBoxLayout;
    ptr_top_layout->addWidget(ptr_one);

    QVBoxLayout* ptr_layout = new QVBoxLayout;
    ptr_layout->setSpacing(0);
    ptr_layout->setContentsMargins(0, 0, 0, 0);
    ptr_layout->addLayout(ptr_top_layout);
    ptr_layout->addWidget(w);
    setLayout(ptr_layout);

    QWidget* ptr_widget = new QWidget(this);
    ptr_widget->winId();
}