Old System software

Hi!

I gave it a try by going back to sensor hub 1.5 and system software 14.4
unfortunately, the barometric diagnostic screen is always wrong, it marks an incorrect altitude of almost 900mt, so the error is already there.
my conclusion is that there is an error in the altitude calculation algorithm, perhaps at the sensor hub level.

In older versions of the system software (<16.5) the calibration algorithm was still able to compensate for it, and the error is evident only when the watch is restarted; after the first calibration, for example when starting an activity, the calibration works and is maintained.
With versions after 16.5 the calibration logic is different and does not compensate for the error, after a few seconds the altitude value is the one calculated by the barometer, in my case much higher than reality, maybe because the GPS altitude is too different from what calculated by the sensor I suppose.
when I start an activity auto calibration is done and after a few seconds the altitude goes up and offset both altitude and elevation gain.

However, I noticed that, even with the latest version, if you use only the barometer, turning off the altimeter, the pressure value is correct for many hours (I compared with another watch).
on the other hand, if you leave the sensor on auto (altimeter and barometer) also the pressure will offset a few seconds after calibration.
now the word to garmin engineers, I have run out of ideas...!