Maintaining text position after applying ItemIgnoresTransformations flag in Qt

Question

I am having QGraphicsView, which has multiple QGraphicsItem's. On QGraphicsView I am performing multiple transformation like zoom-in, zoom-out, Fit-in etc. In QGraphicsItem, I am having few rectangles and some polylines Every polyline has its own name written above it.
Whenever I zoom-in or zoom-out my view, I dont want to change my text size. It should remain same. For that I applied flag QGraphicsItem::ItemIgnoresTransformations.
But after applying this flag, whenever I zoomed-in text changes its position. Means in every zoom-in it should be just above the polyline. But it is changing it's position.

I have taken a help from link but still problem persist.
myText.cpp

myText::myText(const QString &text): QGraphicsSimpleTextItem(text)
{}    
        
QRectF myText::boundingRect() const
{
   QRectF b = QGraphicsSimpleTextItem::boundingRect();
    return QRectF(b.x()-b.width()/2.0, b.y()-b.height()/2.0,
                  b.width(), b.height());
}        
       
void myText::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{
    painter->translate(boundingRect().topLeft());
    QGraphicsSimpleTextItem::paint(painter, option, widget);
    painter->translate(-boundingRect().topLeft());  
} 

myClass.cpp

void myClass:: addText()
{
     QGraphicsSimpleTextItem* text= new QGraphicsSimpleTextItem("Line 1");
     text->setPos(QPointF(some points );
     text->setDefaultTextColor(Qt::black);
     text->setFlag(QGraphicsItem::ItemIgnoresTransformations, true);
     scene->addItem(text);
}      

So question is :

How to ensure that text should not change its position ?