I've tested this on Windows 11 with Qt 6.2.1. When PinchHandler is used the scale (and activeScale) property is incorrectly reported.

For example with the code below:

import QtQuick
import QtQuick.Controls

ApplicationWindow {
    id: root
    visible: true
    width: 640
    height: 480
    title: qsTr("Image Zoom Example")

    Image {
        source: "test.jpg"

        PinchHandler{
            minimumRotation: 0
            maximumRotation: 0
            minimumPointCount: 2
            maximumPointCount: 2
        }
    }

}

when the user pinches on the screen, the image isn't scaled smoothly but there are intermittent jumps that causes "flashing" because the scale value of the pinch handler jumps around during the pinch events.