ActiveExplorer.SelectAllItems doesn't fill ActiveExplorer.Selection

[Burkhard]

I have a problem with the following code, which should process all mails in the current folder and all subfolders, using ActiveExplorer.SelectAllItems and then browsing through ActiveExplorer.Selection.
The weird thing is: when I debug through the code, everything is fine. When I let it run free, ActiveExplorer.Selection is empty (.Count = 0).
Has anybody got a clue?
(For reasons difficult to explain (I will try, if anybody is interested), I must use the "for each item in selection" construct.)

Dim MySelection
Dim NextFolder As folder
Dim pmoCurItem As Object

Dim arFoldersAndSubfolders(maxFolderIndex) As typeFolderLevel
Dim bFolderFound As Boolean
Dim index As Integer, iFolderIndex As Integer

   index = 0
   LoadArrayOfFoldersAndSubfolders Outlook.ActiveExplorer.CurrentFolder, 1, arFoldersAndSubfolders, index
   
   iFolderIndex = 0
   bFolderFound = True
   Outlook.ActiveExplorer.SelectAllItems
   Set MySelection = Outlook.ActiveExplorer.Selection
   Debug.Print "MySelection.Count(A): " & MySelection.Count       'correct: 2
   Do While bFolderFound
      For Each pmoCurItem In MySelection
         If pmoCurItem.Class = olMail Then
               Debug.Print Timer & " | " & pmoCurItem.ReceivedTime & "  " & pmoCurItem.SentOnBehalfOfName & "  " & pmoCurItem.Subject
               '... processing this mail-item ...
         Else
               Debug.Print "skipping: " & pmoCurItem.Class & " " & pmoCurItem.MessageClass
         End If
      Next pmoCurItem
                 
      Set NextFolder = arFoldersAndSubfolders(iFolderIndex).folder

      If NextFolder Is Nothing Then
         bFolderFound = False
         Debug.Print "end of folders"
      Else
         Set Outlook.ActiveExplorer.CurrentFolder = NextFolder
         Outlook.ActiveExplorer.SelectAllItems
         Set MySelection = Outlook.ActiveExplorer.Selection
         Debug.Print "MySelection.Count(: " & iFolderIndex & "): " & MySelection.Count     'wrong: 0
      End If
      iFolderIndex = iFolderIndex + 1
   Loop

The results look like this:

"free run":

MySelection.Count(A): 2
06.12.2021 12:34:40 Szech, Burkhard (EXT) Verschlüsselte Mail mit xlsx-Anhang
14.09.2021 08:48:32 Szech, Burkhard (EXT) Ver- und Entschlüsselungs-Test - intern
MySelection.Count(0): 0
MySelection.Count(1): 0
MySelection.Count(2): 0
end of folders

debugging through the same code:

MySelection.Count(A): 2
06.12.2021 12:34:40 Szech, Burkhard (EXT) Verschlüsselte Mail mit xlsx-Anhang
14.09.2021 08:48:32 Szech, Burkhard (EXT) Ver- und Entschlüsselungs-Test - intern
MySelection.Count(0): 6
skipping: 53 IPM.Schedule.Meeting.Request
skipping: 53 IPM.Schedule.Meeting.Request
06.12.2021 12:29:30 Szech, Burkhard (EXT) Verschlüsselte Mail mit png-Anhang
14.09.2021 08:50:27 Szech, Burkhard (EXT) WG: Ver- und Entschlüsselungs-Test
14.09.2021 08:40:54 Szech, Burkhard (EXT) Ver- und Entschlüsselungs-Test
14.09.2021 08:40:00 Szech, Burkhard (EXT) Ver- und Entschlüsselungs-Test
MySelection.Count(1): 0
MySelection.Count(2): 2
14.09.2021 08:50:00 Szech, Burkhard (EXT) WG: Ver- und Entschlüsselungs-Test
14.09.2021 08:47:00 Szech, Burkhard (EXT) Ver- und Entschlüsselungs-Test - intern
end of folders