Temp folders of Pages and Numbers document not deleted

Hi all,

since upgrading to High Sierra and Server 5.4, I recognize a strange behaviour:

I'm using a Mac mini Server to store my documents, especially those created with Pages and Numbers. Using a share I open them on my MacBook Pro for editing. But with every "Save" an empty folder is created/left in the directory on the server wherein the original document is located. Even after I quit the app, these folders aren't deleted.

If I edit the documents with Pages or Numbers directly on the Mac mini Server, no empty folders left while editing documents or quitting the apps using the same account as for connecting to the share.

Seems to be an issue with file system permissions, which I first recognized directly after upgrading both systems, MacBook Pro and Mac mini Server, to High Sierra.

Any ideas where to start? Many thanks in advance.

Regards and have a nice weekend, Lars