555 - single click doesn't expand the Tree

[HeiWoMa]

I have set:

Click on a Folder in the Tree view shows the content in the File view but doesn't expand the tree in the Tree view. I have to click again on the arrow left from the folder to also expand the tree.
I expected that setting this Option one click would expand the tree in the Tree view and show the content in the File view.
Or what should it do?

[ralfso]

This option opens folder with single click in the file pane.
The option says nothing about expanding tree.