ResetModel leads to ReferenceError

The basic idea of this bug is the follow. I like to load a new model from file. This is done via the Singleton  PlanStorageModel in c++. The function loadPlan in the following example calls calls beginResetModel and EndResetModel. That is all.

Popup {
  id: popup
  closePolicy: Popup.CloseOnEscape | Popup.CloseOnPressOutsideParent
  width: 200
  height: 300
  ColumnLayout {
     Repeater {
        model: PlanStorageModel
        delegate: Button {
           text: nameRole
           onClicked:{ 
              PlanStorageModel.loadPlan(nameRole)
              popup.close() 
           }
        }
     }
   }
}

After the load is finished, the popup should be closed. But this is not possible. I get the Error

qrc:/Intervaltimer/qml/LoadPlanView.qml:22: ReferenceError: popup is not defined

I think is is a bug, because there are no changes done in the UI. The popup still exists. When I switch the calls PlanStorageModel.loadPlan and popup.close() it works as expected