Hi Mark,
Thanks for contacting Syncfusion support.
If your intention is to make the scrollbars scroll automatically as the node/object moves out of the viewable area, then kindly set the following property
//Scrolls both Horizontal and Vertical ScrollBars automatically when mouse moves out of the Viewable area
this.diagram1.Autoscrolling = ScrollBars.Both;
The AutoScrolling property is used to specify the direction for automatic scrolling when the user drags the mouse cursor out of the scrolling area.
Regards,
Naganathan K G