Hello, Alfredo,

The provided clarification helped me a lot to replicate the issue locally. Indeed, when I select a node and start moving the mouse down while the left mouse button is pressed, the tree view scrolls as expected. Once you have all of the desired nodes selected, before releasing the left mouse button, do a little scroll down, then scroll up and you will see the selection is cut, and the first nodes (that are outside the view) have lost selection. The attached gif file illustrates the lost selection.

I have logged it in our feedback portal by making this thread public. You can track its progress, subscribe for status changes and add your comments on the following link - feedback item. 

I have also updated your Telerik points.

Currently, due to complexity of the issue, I would recommend you to perform multiple selection by clicking the first selected node, release the mouse, keep the Shift button pressed and select the end node of the selection. Thus, all the nodes within the range (first clicked node and last clicked node) are selected.

I hope this information helps. If you need any further assistance please don't hesitate to contact me. 

Regards,
Dess | Tech Support Engineer, Sr.
Progress Telerik

Hello, Alfredo,

Following the provided information, I was unable to reproduce the issue you are facing. Please refer to the attached gif file illustrating the behavior on my end with the specified version. Am I missing something? When I select a node and then use the mouse for selecting multiple nodes, the selection is kept properly after releasing the mouse. I have attached my sample project.

Could you please specify the exact steps how to reproduce the problem ? Feel free to modify it in a way to reproduce the experienced issue and get back to me with it so I can investigate the precise case. Thank you in advance. 

I am looking forward to your reply.
Regards,

Dess | Tech Support Engineer, Sr.
Progress Telerik