So I run the same course every day. Same road, same side of the road.
My garmin vivoactive doesn't have barometer, so it is gps elevation with corrections by garmin connect.
And yet every single day, it shows different elevations on the splits, which I have set to half-miles for increased stats/accuracy. The splits with elevation change (vs no change) are the same daily but not the amount itself.
And the overall average elevation is also different, every day.
Why is elevation so useless on garmin?
It is one thing for gps location to be slightly off, but why are the corrections from garmin connect different?