Hello Matthew, 

I am investigating this with the team. The correct approach would be to hook 'onmousemove' on the outer container surrounding the grid and do the following:

public void OnMouseMove(MouseEventArgs e)
{
var cell = this.DataGridRef.GetHitCell(e.PageX, e.PageY)
if(cell != null)
{
console.writeline(cell.RowItem)
}
}

However, GetHitCell is not working at the moment. I have created a private support case for you. It has an ID of C-00221937, and you can access it after signing into your account on the Infragistics website, here: https://account.infragistics.com/support-cases