Bug: Drag-and-Drop Problem with Keyboard Navigation enabled

Enabling keyboard navigation with drag-and-drop task reordering enabled causes odd vertical scrolling behavior when trying to move a task.

To reproduce:

Two examples to demonstrate:

(keyboard navigation disabled): docs.dhtmlx.com/gantt/snippet/625cdff5
(keyboard navigation enabled): docs.dhtmlx.com/gantt/snippet/04456533

  1. Resize the window to be smaller than the chart so the vertical scroll bar appears.
  2. Scroll to the bottom of the list and try dragging one of the last few tasks.

Expected Result
In the first example, dragging behaves as expected.

Actual Result
In the second example with keyboard navigation enabled, the task list jumps to the top and the dragged task hovers somewhere near the top. This can cause confusion for users since the list is not expected to suddenly move when the user starts to drag a task.