QGraphicsEffect on QGraphicsItem causes devicePixelRatio to be ignored

#include <QGraphicsScene>
#include <QGraphicsView>
#include <QGraphicsItem>
#include <QGraphicsDropShadowEffect>
#include <QPainter>
#include <QApplication>
#include <QtGlobal>

int main(int argc, char *argv[])
{
    // large scale factor to make the difference clear
    qputenv("QT_SCALE_FACTOR", QByteArray("2"));
    QApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
    QApplication::setAttribute(Qt::AA_UseHighDpiPixmaps);
    QApplication a(argc, argv);
    QGraphicsScene scene;
    QGraphicsView view(&scene);
    view.setRenderHints(QPainter::Antialiasing);
    // item with a drop shadow effect
    QGraphicsItem *item = scene.addEllipse(0, 0, 60, 60, QPen(Qt::NoPen), QBrush(Qt::red));
    item->setGraphicsEffect(new QGraphicsDropShadowEffect());
    // item without
    scene.addEllipse(100, 0, 60, 60, QPen(Qt::NoPen), QBrush(Qt::red));
    view.show();
    return a.exec();
}