Dragging with HiPen H6 on UBOOK X

I’ve bought an UBOOK X coupled with HiPen H6.

The problems is that my pen sometimes drags when writing or drawing with it.
It normally works but it sometimes detects touching on the screen evens the nib is above it.
So It makes me difficult to write letters correctly.

I use palm rejecting mode(without it, it goes even worse), and Windows 10 is the latest version.

Best regards.