WebEngineView is extremely slow when coexisting with Scene3D

import QtQuick 2.12

import QtWebEngine 1.2
import QtQuick.Scene3D 2.15
import Qt3D.Core 2.15
import Qt3D.Render 2.15
import Qt3D.Input 2.15
import Qt3D.Extras 2.15

ApplicationWindow {
    id: app    width: 800
    height: 600
    visible: true
    
    Scene3D {
        Entity {
            id: sceneRoot
            components: [
                RenderSettings {
                    activeFrameGraph: ForwardRenderer {
                        clearColor: "black"
                    }
                    renderPolicy: RenderSettings.OnDemand                },
                // Event Source will be set by the Qt3DQuickWindow
                InputSettings { }
            ]
        }
    }

    WebEngineView {
        anchors.fill: parent
        url: "https://www.google.com"
    }
}

#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QtWebEngine>

int main(int argc, char *argv[])
{
#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
#endif
    QCoreApplication::setAttribute(Qt::AA_ShareOpenGLContexts);
    QCoreApplication::setAttribute(Qt::AA_UseDesktopOpenGL);

    QtWebEngine::initialize();

    QGuiApplication app(argc, argv);

    QQmlApplicationEngine engine;
    const QUrl url(QStringLiteral("qrc:/main.qml"));
    QObject::connect(&engine, &QQmlApplicationEngine::objectCreated,
                     &app, [url](QObject *obj, const QUrl &objUrl) {
        if (!obj && url == objUrl)
            QCoreApplication::exit(-1);
    }, Qt::QueuedConnection);
    engine.load(url);

    return app.exec();
}