Elevation gain off?

I plotted altitude (grey) and fixed altitude (red, using the topo maps and GPS data) on a chart. They track closely but the fixed line is a lot more noisy due to GPS jitter (I zoomed in on the map) and all those supposed little bumps are counted as elevation gain.

You can use the activity list view to filter for all runs with some climbing since Dec 2022 and disable elevation correction:

I. presume this was before you made changes to limit elev gain being counted if it’s less than x meters?

No it still happens. That threshold is 1.2m currently. I experimented with making it much bigger when using fixed altitude. For this example and the other thread it needs to be 10m to get the climbing to come down to close to the watch number. I think thats too high. The GPS is just too noisy.