nativeEvent always receives empty message with size 0

from PySide6.QtWidgets import QWidget, QApplication

class Window(QWidget):
    def nativeEvent(self, eventType, message):
        print(eventType, message, message.toBytes())
        return super().nativeEvent(eventType, message)

app = QApplication()
window = Window()
window.show()
app.exec()

b'windows_generic_MSG' shiboken6.Shiboken.VoidPtr(Address 0x00000088B40D9D80, Size 0, isWritable False) b''
b'windows_generic_MSG' shiboken6.Shiboken.VoidPtr(Address 0x00000088B40DAF60, Size 0, isWritable False) b''
b'windows_generic_MSG' shiboken6.Shiboken.VoidPtr(Address 0x00000088B40DAF60, Size 0, isWritable False) b''
b'windows_generic_MSG' shiboken6.Shiboken.VoidPtr(Address 0x00000088B40DAF60, Size 0, isWritable False) b''
b'windows_generic_MSG' shiboken6.Shiboken.VoidPtr(Address 0x00000088B40DAF60, Size 0, isWritable False) b''