QML ListView ScrollBar doesn't work properly with variable height items

Please note: This bug is for Qt Quick Controls 2. There was existing bug for QtQuick Controls 1 ( QTBUG-42027 ), which was scoped out when QtQuick Controls 1 was deprecated.

If QML ListView items have variable height, the scrollbar attached to the ListView is inconsistent in its behavior (see the attached images, please note that the scrollbar indeed moves up between images 4 and 5 although the list is being scrolled down).

Scrolling using a wheel of a mouse (or dragging the list from a touch screen, or dragging the list by click-and-hold on mouse button) scrolls the list properly, the scrollbar just constantly changes size and location.

Trying to move the list from the scrollbar on the other hand causes the view to jump up and down uncontrollably, making the scrollbar completely useless.

Attached one-QML application shows all of this well. To reproduce the issue just run the QML file, grab the scrollbar and start dragging down slowly. Soon the scrollbar starts changing size and the items in the view jump up and down, flickering as they come and go.

The issue does not seem to be platform or Qt version dependent.