PyQT5 recreate qml object that references the same python object

test.py

import sys

from PyQt5.QtQml import *
from PyQt5.QtWidgets import *
from PyQt5.QtGui import *
from PyQt5.QtCore import *

class ClassA(QObject):
    bChanged = pyqtSignal()

    def __init__(self, parent=None):
        super().__init__(parent)
        self._b = None

    @pyqtProperty(QObject, notify=bChanged)
    def b(self):
        return self._b
    
    @b.setter
    def b(self, val):
        self._b = val
        self.bChanged.emit()


class ClassB(QObject):
    def __init__(self, parent=None):
        super().__init__(parent)

    @pyqtSlot(QObject, result=bool)
    def equal(self, ref):
        return self == ref



def runQML():
    QApplication.setAttribute(Qt.AA_EnableHighDpiScaling)
    QApplication.setAttribute(Qt.AA_UseDesktopOpenGL)
    app = QApplication(sys.argv)
    engine = QQmlApplicationEngine()

    qmlRegisterType(ClassA, 'CustomClass', 1, 0, 'ClassA')
    qmlRegisterType(ClassB, 'CustomClass', 1, 0, 'ClassB')
 
    engine.load('test2.qml')
 
 
    if not engine.rootObjects():
        return -1
 
    return app.exec_()
 
 
 
if __name__ == "__main__":
    sys.exit(runQML())
    

test2.qml

import QtQuick 2.12
import QtQuick.Controls 2.12
import CustomClass 1.0

ApplicationWindow {
    width: 800
    height: 600
    visible: true

    ClassA {
        b: ClassB {
            id: bb
        }
        Component.onCompleted: {
            console.log('test 1:'+(this.b==bb).toString())
            console.log('test 2:'+(this.b.equal(bb)).toString())
        }
    }


    ClassA {
        b: Rectangle {
            id: rec
        }
        Component.onCompleted: {
            console.log('test 3:'+(this.b==rec).toString())
        }
    }
}

STDOUT:

qml: test 3:true
qml: test 1:false
qml: test 2:true