Started getting the alert immediately after updating to 2018.44.2 last Friday Nov 23rd. Comes up every couple of minutes, then clears again. Repeats constantly. Was advised to take the car into a service centre due to safety concerns (went today) and they told me it is now a known software bug and they are working to fix it in a subsequent release. Wish they had told me that before driving 2 hours to a service centre! Anyway, they said if you move the seat forward/backward a bit, the message will stop popping up (so I was told by Tesla service). Hope this helps someone!