I think this started with 22.18 (or maybe the version before), but all of a sudden elevation gain is way off, like ~300m instead of ~60m.
Never had any issues before.
Had similar issue. Elevation was off most of the time. Activities with the same start/end would have over 200 meters difference between ascent and descent and even activities on flat courses would show…
Elevation has been ALWAYS off since I have FR955 from day 1.
It's because altimeter is influenced from temperature. Here it's winter and when I start a run the altimeter immedeately jumps 50m above actual…
A quick comparison. On the top a run during summer, on the bottom a run in winter. Same roads, it's a round-track I use for 90% of my trainings, you can see between red lines a single "lap" of 2250m.…
Ok, got it.
So I was wondering if your device temperature of the posted December run shows also those zags you can see on the elevation signal.
Anyways, depending on in which country your are located at, I would contact the customer service or vendor to make a claim, asyou got a faulty device since day one.
I live by the sea side and usually ran close to it. I would expect an elevation of 5m or so when on flat but the issue is that the elevation is being shown as constantly flat. Today I did a track session where the elevation used to be 7m. Today was 0m... but when I get some climbs still shows as a flat route and that's the issue!
I think in your case your device is extremly temperature sensitive, causing the fake elevation. I understand / understood that your are on a round course, but it is superimposed with the temperature effekt. Everytime the watch cools down your elevetion rises (besides the real change caused by the ambient pressure change).
Anyways I would try to contact customer service since your device was impacted from the first day.
You might have this issue: 20.26: No altitude change during activity (recorded wrongly as flat with 0m elevation) - Forerunner 955 Series - Running/Multisport - Garmin Forums
Thats a software bug.