I have exactly the same issue on my 9 Peak Pro. The first time I used the watch for indoor skiing, it calculated everything correctly. But now it detects 1 run at best on all my subsequent visits to the indoor location. I tried playing with different settings, like leaving GPS on or off, doing barometer calibration before the training, etc. Nothing seems to help, although the elevation chart at the end of the training looks accurate. It just fails to detect the descents.