On my new FR255, I have been watching the "floors climbed" feature during regular daily activity tracking. I customized a watchface to show this as ascended feet, and it consistently goes up about 8-10 feet after I climb a flight of stairs.
I used the "walk" activity (with GPS) and recorded 300 feet of total ascent. After the activity, the floors and distance tracking metrics also increased as expected from this course. It seemed like every foot of ascent was counted towards floor climbing.
Today, I repeated the same walking course but did not start the walk activity. I just left it on the watchface. The step count went up as expected, and the distance metric seems to pretty accurately reflect the length of the course. But, the floors climbed metric hardly changed at all. It might have gone up 10 feet, as I did not memorize the exact starting value.
I thought this climbing metric was based on the barometer/altimeter sensor, so why should it change behavior when the activity is running?