Cannot get properties of a DBusInterface

According to the documentation here, properties of a QDBusInterface should be accessible through the normal QObject::property() and QObject::setProperty() methods. However, I'm not able to do so.

I've got a DBus object on the session bus with which I'd like to interact. I can see in D-Feet that the interface exposes the property (called "counts") that I expect. However, a small test script is failing to read it. Specifically, this Python script:

session_bus = QDBusConnection.sessionBus()
if not session_bus.isConnected():
    print("Cannot connect to the D-Bus session bus.")
    sys.exit(-1)

iface = QDBusInterface(SERVICE_NAME, '/', INTERFACE_NAME, session_bus)
if not iface.isValid():
    print(session_bus.lastError().message())
    sys.exit(-1)

{{counts_from_remote = iface.property('counts')}}
print(f'Counts from the dbus interface: {counts_from_remote}')

The iface.property('counts') method always returns None, even though the 'counts' property exists on that interface.

I can confirm that the property() method does work correctly for an object that directly inherits QObject:

from PySide6.QtCore import QObject, Property

class MyThing(QObject):
    def _init_(self, parent = None):
        super()._init_(parent)
        self._my_prop = 16

    @Property(int, constant=True)
    def my_prop(self):
        return self._my_prop

def main():
    thing = MyThing()
    p = thing.property('my_prop')
    print(f'The property is {p}')

if _name_ == '_main_':
    main()

It's possible that I'm doing something incorrect here, but it seems like there's at least the possibility that this is a bug.