The slope is incorrect in myrealvideo

[bradchang2005]

Hello,
I took a realvideo through myrealvideo app. I put my iPhone inside of car and climbed on a 12~13km mountain road under around 20 km/hr speed. Everything was good except the slope % wasn't sync with video. The total average slope was fine, but the recorded slope wasn't real. For example, there are lots of slope over 13% and some area under 3% in real, however, the slope is only floating between 5%~9% in the record. And the timing of slope changing is also incorrect. Any suggestion to improve the slope accuracy for my future realvideo recording?

Share the link of myrealvideo I mentioned above:
http://elite-real.com/en/my-realvideo/d ... d=16978026

Thanks,
Brad