Wayland: Application crash during QComboBox item selection

import sys
from PySide6.QtWidgets import QApplication, QWidget, QComboBox, QLabel, QMainWindow, QGridLayout

class Widget(QWidget):
    def __init__(self) -> None:
        super().__init__()
        self._layout=QGridLayout()
        self.lbl = QLabel("Choose item:")
        self.cmbbox=QComboBox()
        self.cmbbox.addItem("item1")
        self.cmbbox.addItem("item2")
        self._layout.addWidget(self.lbl,1,1)
        self._layout.addWidget(self.cmbbox,1,2)
        self.setLayout(self._layout)

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self._widget=Widget() 
        self.setCentralWidget(self._widget)

if __name__=="__main__":
    app = QApplication(sys.argv)
    mw = MainWindow()
    mw.show()
    app.exec()