the firmware version is correct.
I can think that it is mostly related to a missing calibration.
I overwrite the firmware directly on the original nano but as you wrote this shouldn't affect the data in the eeprom. I also used the KD8CEC software manager for donwloading the data. The calibration settings are acccessible from the software?
In any case I think i'll go for calibration procedure as soon
Thank you for the references.