QStandardItem exist in two parent items after drag when itemChanged emited in QStandardItemModel

QStandardItem exist in two parent items after drag when itemChanged emited in QStandardItemModel. I use QTreeView and StandardItemModel for my project.

Steps to reproduce:
1. Run TreeStandardItemModel.zip project.

2. Drag "item" from "group_1" to "group_2"

3. See debug output, from slot that react on QStandardItemModel::itemChanged. Debug output:

"group_1 rowCount: " 1 child name: "item"

"group_2 rowCount: " 1 child name: "item"