QComboBox list cannot display strikeOut text in its list on mac

class TestProxyModel : public QIdentityProxyModel
{
public:
QVariant data(const QModelIndex &index, int role) const override
{
if (role==Qt::FontRole) {
QFont font;
font.setItalic(true);
font.setStrikeOut(true);
return font;
}
return QIdentityProxyModel::data(index, role);
}
};

QComboBox::setModel(new TestProxyModel());