How can i set the value of a column cell from a combobox in Devexpress XtragGrid?

Question

I am trying to set the value of a column cell from a combobox. I have the following

The grid has columns Id, Name , Reference, quite simple.

 private void Form_Load(object sender, EventArgs e)
    {
       
        DataTable dt = GetData(); // populates correctly 
        if (dt.Rows.Count > 0)
        {
            //bind to the grid
            gridControl1.DataSource = dt;
        }                     
        riComboBox = new RepositoryItemComboBox();
        riComboBox.Items.AddRange(companies);
        gridControl1.RepositoryItems.Add(riComboBox);
        gridView1.Columns["Companies"].ColumnEdit = riComboBox;
       
    }
    
    
    
         public static string[] companies= new string[] {  "Company1",
            "company2",
            "company3",
            "company4",
            "company5",
            "company6",
            "company7",
            "company8",
            "company9",
            "company10"};

    
    private void gridView1_CellValueChanging(object sender, 
                 DevExpress.XtraGrid.Views.Base.CellValueChangedEventArgs e)
    {
        
        gridView1.ShowEditor();
        GridView view = sender as GridView;
        DevExpress.XtraGrid.Columns.GridColumn col = view.Columns.ColumnByFieldName("Companies");
        if (col == null) return;            
        gridControl1.BeginUpdate();
        try
        {
            gridView1.CellValueChanging -= new 
            DevExpress.XtraGrid.Views.Base.CellValueChangedEventHandler(gridView1_CellValueChanging);                                
            ComboBoxEdit edit = gridView1.ActiveEditor as ComboBoxEdit;
            if (edit != null)
            {
                string newValue = edit.Text;                   
                gridView1.SetFocusedValue(newValue);
                gridControl1.EndUpdate();
               
            }                
        }
        finally
        {
            gridView1.CellValueChanging += new 
            DevExpress.XtraGrid.Views.Base.CellValueChangedEventHandler(gridView1_CellValueChanging);                
        }
    }

I can see the drop down and select a value, but the value is not saved in the cell and if i add a new row the value is cleared. Any advice on what is wrong ?