Please if anyone could check this video and let me know if you have the same problem, that would be great.
The support team said that it was a normal problem with the tablet, and they wouldn't replace mine.
I wrote on Microsoft forum in detail on this link Touch screen not registering vertical dragging properly - Microsoft Community
It's difficult to believe that this could be the case with so many devices having perfect touch screens these days. If that is the case, I will try to return mine and wait for the Surface Pro.