Page Tree inconsistent auto-scroll behaviour

When focused on a page within page-tree there are three behaviours that can occur. These appear to be inconsistent.

• Selecting a page "Under Scroll 2" for focus
• When using the child-expand link per the image - the first time it will autofocus to the 'Under Scroll 2' link.
• If you minimise the child-expand and repeat the action. the autofocus behaviour no longer occurs
• Selecting a different child-expand link (above the focused page) - the first time will cause the autofocus
• Selecting a different child-expand link (below the focused page) will never cause the autofocus behaviour

The behaviour is expected to be consistent