it happens in a tree with at least 3 levels  when moving node "test" into "test 2" (as a child) the stacktrace points to this line https://github.com/suusan2go/vuetify-draggable-treeview/blob/21762258ef51eb4731916cd83c8037af24293ad7/src/DraggableTreeviewNode.vue#L140 which tells me that that array `children` is not cloned