Hello, Nafise,
Thank you for writing.
I have logged it in our feedback portal. 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, the possible solution that I can suggest is to handle the ItemsChanged event and add a new record to the DataSource manually.
I hope this information helps. Should you have further questions I would be glad to help.
Regards,
Dess
Progress Telerik