I bought a 955 in June this year. After many tests, the watch has found that the cumulative ascent and descent heights calculated by the ABC sensor of the 955 are inaccurate. I often run on a relatively flat road with two slopes. Section, I run back and forth in this section of the road. Compared with the data measured by other brands of stopwatches, I think the data measured by the 955 is not very accurate, and the cumulative increase is much higher than the cumulative decrease. In order to test rigorously, I recently used Garmin Forerunner255 and 955 for comparison test. I adjusted the watch settings to be consistent. The data given by 255 is in line with the actual situation of this road section, while the data of 955 is the same as before, which cannot be accurately obtained on the cumulative altimeter data.
I hope people who understand this problem can help me analyze how to solve the problem and whether it is a quality problem of the watch.