May be, you are right . I’m not expert and I did not mesure it whit GPS. Next week I’m going to make video whith another boards problems, and I’will chek it more accurate.
For a moment, the board accelerated and reached a much higher speed than in the video, maybe 35-40 km / h, but after that it stopped working :(. I could not achieve it again to measure it.
The good news is that the Chinese vendors promised to refund my money.
Wе will see…
I will keep you informed.