PySide6 QListWidget dragging a row to its index deletes the row - qlistwidget

Question

import sys, os
from PySide6.QtCore import *
from PySide6.QtGui import *
from PySide6.QtWidgets import *
from ui_listitem import *
class myItem(QWidget):
def __init__(self, parent = None) -> None:
super().__init__(parent=parent)
self.ui = Ui_rootWidget() # this ui just have 2 text labels horizontal aligned
self.ui.setupUi(self)
class myList(QListWidget):
def __init__(self, parent = None) -> None:
super().__init__(parent=parent)
self.resize(400, 400)
self.setDragDropMode(QAbstractItemView.DragDropMode.InternalMove)
for i in range(10):
wi = QListWidgetItem(self)
wi.widget = myItem(self)
wi.widget.ui.label1.setText(f'text{i}')
wi.widget.ui.label2.setText(f'text{i}')
wi.setSizeHint(wi.widget.sizeHint())
self.addItem(wi)
self.setItemWidget(wi, wi.widget)
if __name__ == '__main__':
app = QApplication(sys.argv)
w = myList()
w.show()
sys.exit(app.exec())
result:
uh..I don't know what it happened. What should I do to get it to work?
I read a post(InternalMove in QListWidget makes item disappear). I tried setDefaultDropAction(Qt.TargetMoveAction) or setMovement(QListView.Free) or both but not worked.
I am using python 3.9.7, pyside 6.2.1, on Windows 10 Pro 20H2 19042.1348 build.
Addition.
A similar but not identical disappearance occurs in a QListView without a custom widget.
import sys, os
from PySide6.QtCore import *
from PySide6.QtGui import *
from PySide6.QtWidgets import *
class myDelegate(QStyledItemDelegate):
def sizeHint(self, option, index):
return QSize(350, 35)
class myList(QListView):
def __init__(self, parent = None) -> None:
super().__init__(parent=parent)
self.resize(400, 400)
self.setDragDropMode(QAbstractItemView.DragDropMode.InternalMove)
self.model = QStandardItemModel(self)
self.setModel(self.model)
self.delegate = myDelegate(self)
self.setItemDelegate(self.delegate)
for i in range(10):
item = QStandardItem(f'text{i}')
self.model.appendRow(item)
self.setDragDropOverwriteMode(False)
if __name__ == '__main__':
app = QApplication(sys.argv)
w = myList()
w.show()
sys.exit(app.exec())
result:
I tried setDefaultDropAction with Qt.MoveAction, Qt.CopyAction or Qt.TargetMoveAction but all not worked.
Are these all originally intended? Please let me know how to move items in listview or listwidget without disappearing. Or maybe it's impossible?