QComboBox popup high decreases when hiding view items

#include "qstyle.h"

#include <QApplication>
#include <QHBoxLayout>
#include <QListView>
#include <QMainWindow>
#include <qcombobox.h>

class MainWindow : public QMainWindow {

private:
    QComboBox *comboBox;
public:
    MainWindow(QWidget *parent = nullptr) : QMainWindow(parent) {
        QHBoxLayout *mainLayout = new QHBoxLayout;
        QWidget *mainWidget = new QWidget(parent);

        QComboBox *comboBox = new QComboBox;

        comboBox->addItem("Item 1");
        comboBox->addItem("Item 2");
        comboBox->addItem("Item 3");
        comboBox->addItem("Item 4");
        comboBox->addItem("Item 5");
        comboBox->addItem("Item 6");
        comboBox->addItem("Item 7");
        comboBox->addItem("Item 8");
        comboBox->addItem("Item 9");
        comboBox->addItem("Item 10");
        comboBox->addItem("Item 11");
        comboBox->addItem("Item 12");
        comboBox->addItem("Item 13");
        comboBox->addItem("Item 14");
        comboBox->addItem("Item 15");
        comboBox->addItem("Item 16");
        comboBox->addItem("Item 17");
        comboBox->addItem("Item 18");

        // number of visible items is less the comboBox->maxVisibleItems()
        QListView *view = qobject_cast<QListView *>(comboBox->view());
        view->setRowHidden(1, true);
        view->setRowHidden(2, true);
        view->setRowHidden(3, true);
        view->setRowHidden(4, true);
        view->setRowHidden(5, true);
        view->setRowHidden(6, true);
        view->setRowHidden(7, true);

        mainLayout->addWidget(comboBox);
        mainWidget->setLayout(mainLayout);

        setCentralWidget(mainWidget);
    };
};

int main(int argc, char *argv[]) {

    QApplication a(argc, argv);
    a.setStyle("Windows"); // bug requires Windows style
    qInfo("%s", a.style()->metaObject()->className());
    MainWindow w;
    w.show();
    return a.exec();
}