cursor shape not preserved if child tool window opens (macOS)

When a Tool type of window is opened over a widget, then the cursor shape set for this widget is not preserved correctly (cursor reverts to the arrow shape).

Consider the following code:

#include <QApplication>
#include <QWidget>

class Widget : public QWidget
{
public:
    Widget(QWidget *parent = nullptr)
    {
        setCursor(Qt::CrossCursor);
    }
protected:
    void mouseReleaseEvent(QMouseEvent *event) override
    {
        auto dlg = new QWidget(this, Qt::Tool);
        dlg->setAttribute(Qt::WA_DeleteOnClose);
        dlg->setAttribute(Qt::WA_ShowWithoutActivating);
        dlg->show();
    }
};

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    Widget w;
    w.show();
    return a.exec();
}

Compile and run this. An empty window will open. It has cross-shaped mouse cursor in it. Click somewhere in the window area. Then a child Tool window get open. If the cursor is out of the area of the opened Tool window but inside the original window, then the cursor will revert from cross-shaped to arrow-shaped cursor. However once the user moves the mouse out of the window area and then move it back, the cross-shaped cursor will be shown again. This happens only on macOS. Has not been observed on Windows. (not tested on Linux yet) It also happens only for Tool type of child. It does not happen for other types (at least not for those which I have tested).