Hi Rafal,
Thank you for contacting Syncfusion support.
We have analyzed your query. We are able to replicate the reported query but it’s not an issue. We have checked with Microsoft DataGrid, when you rebind the itemsource, the vertical scrollbar position changed as top. So the same behavior follow as for SfDataGrid.
Please let us know if you have any query.
Regards,
Muthukumar K