Hi @VanilleTee ⠀ ,
“in the address book there are beside the global also the different departments as subfolders”
You mean that different departments correspond to different address lists, right? Could you remove all private information and share a screenshot of this?
Please clarify whether the update takes effect in OWA or Outlook online mode. If yes, it is recommended that you modify the local offline address book file suffix of the following path to .old, and then re-execute "Download Address Book" on the Outlook client to see if it works.
C:\Users%username%\AppData\Local\Microsoft\Outlook\Offline Address Books
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