TreeView is very slow. Any performance tips?

I’m using the treeview to visualize  a filesystem based on a directory list. This list came from a hardrive.

I feed this list of strings  to the function shown below.

It is the same function from the desktop app.

The desktop app can  populate  the winforms treeview  with  500,000 items and display them without any lag.

The Wisej Treview cant even display 5,000 items without choking.

How can I get better performance?

Snippet

TreeView1.Nodes.Clear()
        TreeView1.Nodes.Add(PopulateTreeNode2(paths, "\"c))

Snippet

Public Function PopulateTreeNode(paths As String(), pathSeparator As String) As TreeNode
       Dim thisnode As New TreeNode()
 
       If paths Is Nothing Then
           Return Nothing
 
       Else
 
           Application.StartTask(Sub()
 
 
                                     thisnode.Text = My.Settings.JobName
                                     Dim currentnode As TreeNode
                                     Dim cachedpathseparator As Char() = pathSeparator.ToCharArray()
                                     For Each path As String In paths
                                         currentnode = thisnode
                                         For Each subPath As String In path.Split(cachedpathseparator)
                                             If currentnode.Nodes(subPath) Is Nothing Then
                                                 currentnode = currentnode.Nodes.Add(subPath, subPath)
                                             Else
                                                 '   currentnode = currentnode.Nodes(subPath)
                                             End If
                                             Application.Update(TreeView1)
 
                                         Next
                                         Application.Update(Me)
                                         
                                     Next
 
                                 End Sub)
 
 
       End If
 
 
       MsgBox("OK")
       Return thisnode
 
   End Function