Altimeter woes in watch mode

Now at +25 even though I am still at the same height. There have been no changes in the air pressure today so that can’t be the reason...

When you calibrate the altimeter, the options with auto are "During Activity"("Continuous", "At Start" and "off"), and "Not During Activity", ("on" and "off"). So continuous, is only during an activity (it's using GPS, (maybe to get a map reference to look it up?)). "Not During Activity" may be any time GPS gets a fix, it calibrates or something (such as using GPS to set the time)

Interesting. So in watch mode (not during activity) per what DCR said it can try to use the phone's location data with the maps, but only during the users configured sleep time. So it calibrates overnight.

What’s the advantage to continuously auto calibrate rather than manually doing so based on known data?

People have found with the original F5 series that, if you ascend far enough, the true elevation and the watch barometer-based reading move further and further apart, even with an initial precise manual calibration and little change in weather conditions. The process described in the link in my last post should stop that happening, while paying enough attention to the barometer that you're not locked to the spatial resolution of the elevation map, or thrown off by inappropriate map readings where you're walking along a contour line and poor GPS reception moves your recorded location to the side of the path (so the watch would look in the wrong location on the map for your elevation).