Sonoff 3.6.0 DIY v2.0

Question

I bought a Sonoff Basic R3 to use use in DIY mode with a Raspberry Pi. The firmware I've confirmed is 3.6.0 so DIY v2.0. The DIY connection process works fine using 10.10.7.1 and it connects to the router and I have assigned it a static IP address. I can ping it no problem.

Ping statistics for 10.0.0.35:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 3ms, Maximum = 97ms, Average = 53ms 

But when I run the Raspberry Pi (connected to the same router with the same subnet etc) http post json code

import requests
import json

#API details
url = "https://10.0.0.35:8081/zeroconf/switch"
body = {"deviceid": "",  "data": {"switch": "on"} }
headers = {'Content-Type': 'application/json'}

#Making http post request
response = requests.post(url, headers=headers, data=body, verify=False)
print(response)

It just hangs up until I keyboard interrupt (Ctrl-C). I'm pretty sure it is some sort of connection/port issue as the outcome of the code is the same whether or not the device is powered up (I've also tried a number of variations of the json post code using info, switch: off etc all with the same outcome).

^CTraceback (most recent call last):
  File "/home/pi/Programmes/sonoff3.py", line 10, in <module>
    response = requests.post(url, headers=headers, data=body, verify=False)
  File "/usr/lib/python3/dist-packages/requests/api.py", line 119, in post
    return request('post', url, data=data, json=json, **kwargs)
  File "/usr/lib/python3/dist-packages/requests/api.py", line 61, in request
    return session.request(method=method, url=url, **kwargs)
  File "/usr/lib/python3/dist-packages/requests/sessions.py", line 542, in request
    resp = self.send(prep, **send_kwargs)
  File "/usr/lib/python3/dist-packages/requests/sessions.py", line 655, in send
    r = adapter.send(request, **kwargs)
  File "/usr/lib/python3/dist-packages/requests/adapters.py", line 439, in send
    resp = conn.urlopen(
  File "/usr/lib/python3/dist-packages/urllib3/connectionpool.py", line 699, in urlopen
    httplib_response = self._make_request(
  File "/usr/lib/python3/dist-packages/urllib3/connectionpool.py", line 445, in _make_request
    six.raise_from(e, None)
  File "<string>", line 3, in raise_from
  File "/usr/lib/python3/dist-packages/urllib3/connectionpool.py", line 440, in _make_request
    httplib_response = conn.getresponse()
  File "/usr/lib/python3.9/http/client.py", line 1347, in getresponse
    response.begin()
  File "/usr/lib/python3.9/http/client.py", line 307, in begin
    version, status, reason = self._read_status()
  File "/usr/lib/python3.9/http/client.py", line 268, in _read_status
    line = str(self.fp.readline(_MAXLINE + 1), "iso-8859-1")
  File "/usr/lib/python3.9/socket.py", line 704, in readinto
    return self._sock.recv_into(b)
KeyboardInterrupt

So after 8 hours of trying yesterday and another few today I'm at a loss so any pointers as to what else to try would be great. Thanks.