@Solla-topee 

Thanks for the prompt reply. Seems like there might be some hope yet.  Thanks.

    1. What app/program are you using to stream the camera via the Onvif connection?

I'm using a modified version of the open source script quoted in my message, the essense of the code is something like:

pullpoint_req = pullpoint_service.create_type('PullMessages')
pullpoint_req.MessageLimit=10
pullpoint_req.Timeout = (dt.timedelta(days=0,hours=0,seconds=1))
while True:
    camera_messages = await pullpoint_service.PullMessages(pullpoint_req)  
    if camera_messages:
        for key in camera_messages: 
            print(f"\n--------------\n{key=}\n{camera_messages[key]=}\n--------------\n")
    else:      
        sleep(cfg.idleSleepSecs)
  
  2. Can you receive person-detected notifications on your phone or the Tapo app?

Yes that works.

    3. You can refer to the instructions below to stream the camera via iSpy and then check if the person detection notification via Onvif works.
        How to view Tapo camera on PC/NAS/NVR through RTSP/Onvif Protocol

I don't think there is an ispy for my platform (raspberry pi 4 raspbian/debian OS).

What I receive is a series of jason messages - which don't appear to have any attributes to distinguish motion-detections from person-detections - but I could be wrong on this as I'm just guessing.  Each jason message appears to be something like:

key='NotificationMessage'
camera_messages[key]=[{
   'SubscriptionReference': {
       'Address': {
           '_value_1': None,
           '_attr_1': None
       },
       'ReferenceParameters': None,
       'Metadata': None,
       '_value_1': None,
       '_attr_1': None
   },
   'Topic': {
       '_value_1': 'tns1:RuleEngine/CellMotionDetector/Motion',
       'Dialect': 'http://www.onvif.org/ver10/tev/topicExpression/ConcreteSet',
       '_attr_1': {
   }
   },
   'ProducerReference': None,
   'Message': {
       '_value_1': {
           'Source': {
               'SimpleItem': [
                   {
                       'Name': 'VideoSourceConfigurationToken',
                       'Value': 'vsconf'
                   },
                   {
                       'Name': 'VideoAnalyticsConfigurationToken',
                       'Value': 'VideoAnalyticsToken'
                   },
                   {
                       'Name': 'Rule',
                       'Value': 'MyMotionDetectorRule'
                   }
               ],
               'ElementItem': [],
               'Extension': None,
               '_attr_1': None
           },
           'Key': None,
           'Data': {
               'SimpleItem': [
                   {
                       'Name': 'IsMotion',
                       'Value': 'true'
                   }
               ],
               'ElementItem': [],
               'Extension': None,
               '_attr_1': None
           },
           'Extension': None,
           'UtcTime': datetime.datetime(2025, 1, 22, 7, 7, 53, tzinfo=datetime.timezone.utc),
           'PropertyOperation': 'Changed',
           '_attr_1': {
       }
       }
   }
}]

Perhaps I need to do some more research.  Any pointers are appreciated, but I fully understand that you might not have time to nursemaid every coder who decides to try and write a client.

Best Regards