Hello, I was experiencing the same issue with abnormally high elevation gain after every outing, whether running, trail running, or cycling. This was true regardless of the wind conditions: light, strong, or nonexistent. I tried all the advice on the forum, then realized that the atmospheric pressure reading wasn’t stable when I stayed in one place (home, work, etc.). I then contacted someone on the Suunto chat who advised me to return the watch to have the atmospheric pressure sensor checked. The process took two weeks (sending, repairing, and returning the watch), and indeed, the sensor was faulty. After the watch was returned, the pressure reading was completely stable when I was stationary and the weather was stable. The elevation gain returned to normal, with no significant difference compared to Strava or any other comparative measurement.
Problem solved.
On reflection, the elevation measurement is carried out in FusedAlti mode, therefore via GPS and pressure sensor between GPS points, but if the sensor is unstable, this explains the “waves” on the elevation curve and therefore the overestimation of ascents and descents.
No relation with à firmware update.
