Hi Elizabeth,
Thank you for contacting Telerik support.
I would like to clarify that
RadItemDragDropManager example does not support scrolling and you can Drag&Drop only visible items. I can suggest checking the items in
BeginDrag method. For example:
I hope this will be useful for you. Should you have further questions, I would be glad to help.
Greetings,
Peter
the Telerik team