The top grid scrolls when the cursor hovers near the bottom

The top grid scrolls when the cursor hovers near the bottom of the grid. how to turn this off?

The auto-scroll can occur in two cases
a) enableLightMouseNavigation mode used , in such case grid automatically move row under cursor in visible part of grid , which cause auto-scrolling.
b) while d-n-d , grid auto-scrolls if drag moved to bottom area of grid

To disable [a] - just not use lightNavigationMode
[b] can’t be disabled without code modification