In GtkTreeView with multiple selection mode, How does the cursor behave?

In GtkTreeView with MULTIPLE mode enabled, How does the cursor behave? I’m a little confused, since I thought that cursor automatically gets changed to the currently selected node in the tree. So am I missing something?

For example, in the video above, if I select using the “shift+down” keys two nodes(4, and 5 in this case), then I unselect any one of them(5). The cursor position becomes at the unselected node. So whenever I hit “shift+down” again, only node 5 will be selected. Shouldn’t the two nodes(node 4 and 5) be selected?