VB.Net DatagridviewComboBoxColumn CellClick behavior

Question

I have a DatagridviewComboBoxColumn populated from a DataTable and whenever I click on any part of the DataGridViewComboBoxCell the first value of the list shows up as it had been clicked. However, when I move the focus to another cell without selecting a value, it disappears.

Strangely, the behavior is not consistent if I apply the ComboBox values with .Items.Add(" "). Can anyone shed some light on this issue. Here is a sample code and a gif image:

Public Class Form1

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    DataGridView1.Rows.Add()
    DataGridView1.Rows.Add()

    ''DataGridViewComboBoxColumn1
    DataGridViewComboBoxColumn1.Items.Add("Name1")
    DataGridViewComboBoxColumn1.Items.Add("Name2")

    'DataGridViewComboBoxColumn2
    Dim dt As New DataTable
    dt.Columns.Add("id")
    dt.Columns.Add("name")
    dt.Rows.Add("1", "Name1")
    dt.Rows.Add("2", "Name2")
    With DataGridViewComboBoxColumn2
        .ValueMember = dt.Columns(0).ColumnName
        .DisplayMember = dt.Columns(1).ColumnName
        .DataSource = dt
    End With
End Sub

End Class

Answer 1

I found a way to correct the behavior by referring to this post: DataGridComboBoxColumn shows first value on CellEnter

Here is the code I have used:

    Private Sub DataGridView1_EditingControlShowing(ByVal sender As Object, ByVal e As DataGridViewEditingControlShowingEventArgs) Handles DataGridView1.EditingControlShowing
      If TypeOf e.Control Is ComboBox Then
          Dim comboBox As ComboBox = DirectCast(e.Control, ComboBox)
          If DataGridView1.CurrentCell.Value Is Nothing Then comboBox.SelectedIndex = -1
      End If
    End Sub