I have submitted the following to my service request.
"Hi xxx, thank you for your call yesterday. As discussed I have charged the car overnight with Intelligent Octopus (IO) and have observed the same behaviour reported in the service request.
[18/5_17:27] IO app opened to enable smart charging with a target charge level of 80% by 08:00.
[18/5_17:32] Charging cable connected. Charging starts automatically. Charging stopped manually in car. Charge limit 90% in car.
[18/5_17:40] Check Tesla app. Charging remains stopped.
[18/5_17:51] Check IO app. Smart charging scheduled to charge 12:30-01:30, 02:00-04:00, 04:00-04:30 & 04:30–5:00.
[18/5_17:53] Charging remains stopped. Tesla and IO apps running in background.
[18/5_19:11] Check Tesla app. Car charging at 32A. Charging stopped manually. 5kWh was added, indicating charging started unexpectedly circa 40 minutes earlier, around 18:30.
[18/5_19:49] Check Tesla app. Car not charging. Charging starts automatically. Charging stopped manually.
[18/5_20:35] Check Tesla app. Car not charging. Charging starts automatically. Charging stopped manually.
[18/5_21:40] Check Tesla app. Car not charging. Charging starts automatically. Charging stopped manually.
[18/5_23:07] Check Tesla app. Car not charging. Charging starts automatically. Charging stopped manually.
[19/5_07:35] Check Tesla app. Car not charging. Charging starts automatically. Charging stopped manually. Smart charging disabled in IO app.
[19/5_08:44] Check Tesla app. Car not charging. Charging starts automatically. Charging stopped manually.
[19/5_10:06] Open driver’s door. Car not charging. Charging starts automatically. Charging stopped manually. Charging cable disconnected.
There are three significant events, where charging is starting automatically, despite being stopped when the car wakes [18/5_19:11, 19/5_08:44 & 19/5_10:06]. Two of which were not coincident with being controlled by IO. This behaviour seems contrary to the advice to leave the car plugged into a charger when not in use and is causing the car to charge unexpectedly during peak rates".