Help with STreeView

Hey, I created a Slate TreeView widget.
It works fine until I extend the first level of the tree.
Then it dosent allow me to select any of the children (That are in the second level of the tree), And it dosent even show me the subfolders of the next level of the tree.
Im aware that I need to tinker with the
.OnSetExpansionRecursive and stuff but even after looking at the surce code of other classes I cant seem to figure it out.
Pics included to show you whats going on.