Start HelloTreeTableView, open Filesystem Browser, click Debug selection.
Expand some folder (folder1) and select any of its subfolders.

Cell [ row: 12, column: 0]

Now, collapse the folder1 by clicking on a triangle.
The selection moves to the folder1 and this gets printed in the console

Cell [ row: 11, column: 0]
Cell [ row: 11, column: 0] Cell [ row: 11, column: 1]
Cell [ row: 11, column: 0] Cell [ row: 11, column: 1] Cell [ row: 11, column: 2]

Now, expand any folder before the folder1 (preferably a folder with not too many items).
The selection of the Size and Modified columns moves to the other items, focus remains on the Modified column and the selection of the Name column either remains or moves depending on whether the last folder was expanded before or not (this is RT-39674).

This happens on 8u40, on 8u25 it doesn't move the selection after collapsing the folder1 so this seems to be a regression after some fix in 8u40.