Altimeter drops 100 Meters at the start of an activity

Hi all,

every time I start an running activity on my Fenix 6X Sapphire with 9.0 installed, the altimeter drops about 100 Meters immediately and rises continuously during the run about 70 Meters in 45 Minutes, so that the difference at the end is about 30 Meters to the original height. As you can see on the screenshot my track starts at 241 Meters, continuously rises to 338 Meters and ends at 230 Meters. This issue is reproducible.

I have auto calibration completely turned off and always calibrate the watch manually before I start an activity. Has anyone an idea how to stop this strange behavior or is experiencing the same? May the altimeter sensor be broken or could it be another software issue?

Thanks in advance for your help!

0 eezytiger over 5 years ago

I have seen this behaviour only once, at the beginning of a hike (daily dog walk), but the drop was only 10m. The rest of the activity was recorded correctly in terms of elevation gain/loss, but with all numbers 10m below actual. Mostly everything tracks well, without unusual deviations.

That said, yesterday I went mountain biking. Altitude was set manually at the start, with GPS calibration disabled, and within 4 seconds of pressing start the watch had gained two meters while I sat still on my bike. Hardly a disaster, but also not expected or explainable.

If you're seeing -100m every time I suggest a chat with Garmin. Good luck.