tree node expand only loads sub-nodes first time

Hi

I have a CRUD JSON tree with 2 levels . The first level of nodes is loaded from the server at startup. Clicking on a node's expand icon loads the sub nodes OK (if first time). But if I collapse the node and then expand it again no new load takes place.

I want to load a node's sub nodes on every expand.

Peter

tree node expand only loads sub-nodes first time