I actually wanted to check if the motor had just started a regeneration cycle, and I took the opportunity to create another "start log" using a different battery.
I noticed something strange in the log.
(Background: Approximately 14 km driven, regeneration has been running for 485 seconds, the vehicle was just parked to retrieve a laptop.)
Okay, Excel has been conquered, and a scatter plot has been implemented.
Yes, those 90 degrees are definitely correct.
I've now also reviewed all the other logs containing temperature data, and they are all fine.
It was a huge coincidence that I saw the jump.