[Reg 6.6.6 -> 6.7]: QML ListView don't update/respect model data/delegates X-position

Starting point:
In my far more complex app I have a overview where a QML ListView with names/data are shown and there is an option to drag the items on the X-axis, to fix them in different columns. The position of the items can also be saved, and the data is saved/holding in a QAbstractListḾodel and (originally) exposed to QML from Python. The app was orignally written with Python 3.12 and PySide 6.6.1.

Issue:

https://youtu.be/K3MtL0wY9Gg?si=D1QIneRrmpFnhZVA

While updating to PySide 6.8 I've realised the X-Axis calculation is not updated/respected and the ListView don't set the x value of the delegate to the correct value. Also resizing, max- and minimizing leads X to be set to 0, even tough the data in the model is unchanged and it should set the X-value correctly.

My Investigation showed, it's also happening in PySide 6.7 and could only be repaired to original state by rolling back to PySide 6.6.x (Linux and Windows).

I've created a minimal example, replicating the QML ListView with dragging on X-Axis.

EDIT: minimal example behaves in Fedora Wortstation with Python 3.11 and PySide 6.6.3 as expected (Elements start on there position and window can be resized, maximized, minimized, and elements moved). Fails on the same system with Python 3.13 and PySide 6.8.1.

EDIT 2: added a CPP file to move this to Qt bug section