Ios Client 2.25.1 & SMB exterrnal storage - renaming/deleting not possible

We‘re using ios client 2.25.1 and Nextcloud 17.0.1. Renaming/deleting files on external storages (SMB) isn‘t possible because the client is refusing it with the message „you got no rights to delete/rename files“.
With older versons of the ios client or with the web client it is possible.

There are no hints in any log available that could explain this behaviour.