Multiple inheritance gives TypeError in __init__

from PySide6 import QtCore

class CommunicationBase(object):
    def __init__(self, engine):
        self._engine = engine

class SiteCommunication(QtCore.QObject, CommunicationBase):
    proxy_closing = QtCore.Signal()
    proxy_created = QtCore.Signal()

    def __init__(self, engine):
        CommunicationBase.__init__(self, engine)
        QtCore.QObject.__init__(self)

class DesktopEngineSiteImplementation(object):
    def __init__(self, engine):
        site_comm = SiteCommunication(engine)
        site_comm.proxy_closing.connect(self._on_proxy_closing)
        site_comm.proxy_created.connect(self._on_proxy_created)

    def _on_proxy_closing(self):
        print("Proxy closing")

    def _on_proxy_created(self):
        print("Proxy created")

engine = "foo"
DesktopEngineSiteImplementation(engine)

024-06-05 14:01:44,034 [342828 ERROR sgtk.ext.shotgun_desktop.startup] Fatal error, user will be logged out.
Traceback (most recent call last):
    File "${PATH_TO}/python/shotgun_desktop/startup.py", line 951, in main
        exit_code = __launch_app(app, splash, user, app_bootstrap, settings)
    File "${PATH_TO}/python/shotgun_desktop/startup.py", line 425, in __launch_app
        engine = __start_engine_in_zero_config(app, app_bootstrap, splash, user)
    File "${PATH_TO}/python/shotgun_desktop/startup.py", line 597, in __start_engine_in_zero_config
        return mgr.bootstrap_engine("tk-desktop")
    File "${PATH_TO}/sgtk/tk-core/python/tank/bootstrap/manager.py", line 492, in bootstrap_engine
        engine = self._start_engine(tk, engine_name, entity)
    File "${PATH_TO}/sgtk/tk-core/python/tank/bootstrap/manager.py", line 1217, in _start_engine
        engine = tank.platform.start_engine(engine_name, tk, ctx)
    File "${PATH_TO}/install/core/python/tank/platform/engine.py", line 3044, in start_engine
        return _start_engine(engine_name, tk, None, context)
    File "${PATH_TO}/install/core/python/tank/platform/engine.py", line 3204, in _start_engine
        engine = class_obj(tk, new_context, engine_name, env)
    File "${PATH_TO}/sgtk/tk-desktop/engine.py", line 62, in __init__
        Engine.__init__(self, tk, *args, **kwargs)
    File "${PATH_TO}/install/core/python/tank/platform/engine.py", line 172, in __init__
        self.init_engine()
    File "${PATH_TO}/sgtk/tk-desktop/engine.py", line 142, in init_engine
        self.__impl = tk_desktop.get_engine_implementation(interface_type)(self)
    File "${PATH_TO}/sgtk/tk-desktop/python/tk_desktop/desktop_engine_site_implementation.py", line 40, in __init__
        self.site_comm = SiteCommunication(engine)
    File "${PATH_TO}/sgtk/tk-desktop/python/tk_desktop/site_communication.py", line 43, in __init__
        QtCore.QObject.__init__(self)
TypeError: CommunicationBase.__init__() missing 1 required positional argument: 'engine'