CGAffineTransformScale doesn't work on iPhone12 or iOS 14

on iPhone X, or iOS 13.X , I used CGAffineTransformScale to respond to pinch gesture and enlarge photos on an UIViewController from  UIViewController <UIGestureRecognizerDelegate>

code snippet is as follows and used to work fine, but has no effect on iOS 14 or iPhone12.

Any hints?

---

 static CGFloat sPreviousScale = 0.0;

    if([recognizer state] == UIGestureRecognizerStateEnded) {
        sPreviousScale = 1.0;
        return;
    }

    CGFloat newScale = [recognizer scale] - sPreviousScale +1.0;

    CGAffineTransform currentTransformation = self.mImageView.transform;

    CGAffineTransform newTransform = CGAffineTransformScale(currentTransformation, newScale, newScale);

    // perform the new transform
    self.mImageView.transform = newTransform;

  sPreviousScale = [recognizer scale];