[Performance] Fresco on iPad - Lag with some brushes

I am experiencing a lag with some brushes in Adobre Fresco, Apple Pencil II and iPad Air 4th gen. It is visible in the video when I choose Graphite soft. It feels like there is a lag after I touch the screen with Pencil and it doesn't respond to light teach. 

Lag with Apple Pencil 

Is it how it is supposed to work, a bug or a problem with the Pencil?

[Renamed by Mod]