Auto-scrolling breaks when dragging and dropping an item in QTreeView.

QTreeView in Qt 6.5.7 causes issues with the auto-scrolling feature during a drag-and-drop event. This feature worked as expected in Qt 5.15.17 but fails in the later version.

Steps to Reproduce

1. Build and run the attached project with Qt 5.15.17.

• • Expected Behavior: When dragging a tree item to the bottom of the view, the tree begins to auto-scroll without interruption.

1. Build and run the project with Qt 6.5.7.

• • Observed Behavior: The tree begins to scroll but stutters and eventually stops. Moving the mouse pointer within the scroll area may cause temporary scrolling, but it does not auto-scroll consistently.