To reproduce:
- Subscribe to the SelectionChanged event.
- Move the mouse while holding the left button.
- The event is fire multiple times.

Workaround:
VirtualGridCellInfo prevCell = null;
private void OnGridSelectionChanged(object sender, EventArgs e)
{
    if (prevCell != gvItems.CurrentCell)
    {
        _selectionChangedCount++;
    
        tbLog.AppendText("Selection changed " + _selectionChangedCount + "\r\n");
    }
    prevCell = gvItems.CurrentCell;
}