Altimeter -2216m

how is the barometer reading?

1037.4 so correct for where I am now

What is the Sensor Hub version?

Does the temperature measurement (internal sensor) work correctly?

If you calibrate the altimeter and check the barometer, then switch the watch off and back on, are these close to the previous values or very much off?

Sensor Hub version 33.13

Calibration then reboot does not change anything.

I've also reset settings and data without any change

And does the temperature measurement (internal sensor) work correctly? If it shows an insane value, it is likely a hardware problem.

But in either case, doing a software reinstall is worth a try.

Température seems good to me.

I've already done an hard reset. Is it different from software reinstall?

Temperature is indeed fine. It is a strange problem. Usually if the altimeter is extremely off, the barometer is also off. The temperature sensor is used to correct the alti/baro sensor for temp, changes, and if that is broken alti and baro will not work correctly, But yours is OK.

It is unlikely to be dirt in the sensor port because the baro sensor works fine, so soaking the watch won't help.

It can't be settings because you did a hard reset, all settings are back to standard.

It is not likely to be auto-calibrate with an incorrect altitude taken from your phone's location, there are no valid locations at -2200 meters. You could try not connecting to Wifi or phone for 24 hours and see what happens though.

I assume that a hard reset (i.e. Reset with Delete Data and Reset Settings) implicitly reinstalls the software, but you could try it, maybe it re-initializes differently.

Unless someone else has an idea, I think you should call Garmin Support.

After software reinstall and calibration I got 735m so perfect. But after wake up this morning back to -2216m... 

I'm going to try no wifi/phone connection for few hours.

IMHO it's a bug because calibration is good. Was hoping 22.22 solved this issue but not.

ben-ben said:

I'm going to try no wifi/phone connection for few hours.

Try during the night. Altimeter auto-calibration is around 4 AM.