CHM File in .Net project: can't reach the topic Id correctly

Context:

I made a chm file with the free version of Help'n'Doc to use it in a .Net Application. This help has to be call by clicking on a button and open on the proper help page.

Problem:

Instead of having this (the correct page in the Contents tab):

I got this:

Details:

Here's the code to call the help: Help.ShowHelp(Me.btnHashtagHelp, pathHelpFile, HelpNavigator.TopicId, "6")

Here's the page in Help'N'Doc:

What did i do wrong?

Found the reason of this strange behaviour: the chm files that i called was not local but stored on a professionnal private network. To fix the problem, i copy the file in a local Path that I create.

Here's my code to manage the chm file from "not local" to "local"

    Private Sub HelpFileManagement()
        ''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
        '''                               Manage the Help File Storage                               '''
        '''  1) Check if the local folder FOLDER1 "C:\Users\USERNAME\Documents\MyAppName" exist. If not, the folder is created
        '''  2) Check if there is a MyAppName-help.chm in FOLDER1 . If not, the file is copied from the network folder to FOLDER1
        '''  3) If there is already a file, check last modification date between the local file and the network file
        '''  
        Dim strHelpFolder As String = My.Computer.FileSystem.SpecialDirectories.MyDocuments & "\MyAppName\"
        Dim dirHelpFolder As DirectoryInfo
        Dim strHelpFileName As String = "MyAppName-help.chm"
        Dim strHelpSourceFile As String = System.IO.Path.Combine(Application.StartupPath, "MyAppName-help.chm")
        Dim dateSourceHelpFile As DateTime
        Dim dateCurrentHelpFile As DateTime
        Dim strMsgException As String = "Problème dans la gestion du fichier d'aide." & vbCrLf & strMsgErrorTellYourAdmin

        Try
            '1)
            If Directory.Exists(strHelpFolder) = False Then
                dirHelpFolder = Directory.CreateDirectory(strHelpFolder)
            End If
            strPathHelp = My.Computer.FileSystem.SpecialDirectories.MyDocuments & "\Dumbow\"
            strPathHelpFile = System.IO.Path.Combine(strPathHelp, "Dumbow2-help.chm")

            '2)
            If File.Exists(System.IO.Path.Combine(strHelpFolder, strHelpFileName)) = False Then
                File.Copy(strHelpSourceFile, System.IO.Path.Combine(strHelpFolder, strHelpFileName))
            Else
                '3)
                dateSourceHelpFile = File.GetLastWriteTime(strHelpSourceFile)
                dateCurrentHelpFile = File.GetLastWriteTime(System.IO.Path.Combine(strHelpFolder, strHelpFileName))
                If dateSourceHelpFile <> dateCurrentHelpFile Then
                    File.Copy(strHelpSourceFile, System.IO.Path.Combine(strHelpFolder, strHelpFileName), True)
                End If
            End If

        Catch ex As Exception
            MsgBox(strMsgException & vbCrLf & ex.Message, MsgBoxStyle.Information, strMsgBoxGeneralErrorTitle)
            Exit Try

        End Try

    End Sub