Thanks for the quick reply.
I have also tried various earlier firmwares (4.3 and 3.9). Both with the same result.
I can eliminate point 2 – I was very careful to leave the multimeter connected during calibration.
What exactly does point 1 mean – is there anything I can do?
I’m also afraid it’s a problem with the ADC for the input current.
Could a new STM32 controller solve the problem?
Kind regards
Philip