[Reg 5.15 -> 6.2] QML Binding on new object not re-evaluated

Simple qml bindings may fail to re-evaluate when they reference an object that has just been created.

For example in the below image I have a simple qml application with two buttons. The first button either creates a Rectangle object and sets it's width to 1200 or deletes the previously created Rectangle. The second button simply prints the width of the Rectangle if it exists.

If I spam the first button (see in the attached gif) you should see that the buttons text sometimes shows 1200 (CORRECT) but also sometimes shows 0 (INCORRECT). This appears to be totally random, sometimes it happens right away, sometimes it takes 30+ clicks but it does eventually happen.

The binding that is not re-evaluating is simply:

text: root.rectItem?.width ?? "Create Object" 

I.e. display the width of rectItem if it exists.

If I click button 2 while button 1 shows "0" it will correctly console.log the width of the rectItem as 1200.

I have attached the full qml example for reference.