Why the cmbcategory.selectedindex change is not working on if condition

Imports System
Imports System.Data
Imports System.Data.SqlClient

Public Class displayitemcodes
    Dim con As SqlConnection
    Dim cmd As SqlCommand
    Dim da As SqlDataAdapter
    Dim dt As DataTable
    Dim s As String

   
    Private Sub cmbcategory_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmbcategory.SelectedIndexChanged
        If cmbcategory.SelectedItem.ToString() <> "--Select Category--" Then
            MsgBox("Done")
        End If
    End Sub

    Private Sub displayitemcodes_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        con = New SqlConnection("server=ADMIN-PC\SQLEXPRESS;database=stocktracker;Integrated security=true")
        s = "select distinct category from mstitems"
        da = New SqlDataAdapter(s, con)
        dt = New DataTable()
        da.Fill(dt)

        Dim newCustomersRow As DataRow = dt.NewRow()

        newCustomersRow("category") = "--Select Category--"
        dt.Rows.InsertAt(newCustomersRow, 0)

        With cmbcategory


            .DisplayMember = "category"
            .ValueMember = "category"
            .DataSource = dt




        End With
        cmbcategory.Refresh()
    End Sub
End Class