The cell navigation is wrong when the grid is ungrouped. Steps to reproduce: 1. Enable cell selection mode 2. Navigate with keyboard 3. Group the RadGridView by one column 4. Navigate with keyboard 5. Ungroup the RadGridView's rows 6. Now Keyboard navigation is wrong.

Same behavior appears with the default selection mode:

- Group the grid and select a row in a group

- Ungroup and use the keyboard to navigate between the rows => it navigates only the rows that were in the group where we have selected a row

WORKAROUND: 

private void radGridView1_GroupByChanged(object sender, Telerik.WinControls.UI.GridViewCollectionChangedEventArgs e)

{

    GridViewRowInfo row = this.radGridView1.CurrentRow;

    this.radGridView1.CurrentRow = null;

    this.radGridView1.CurrentRow = row;

}