Cannot create subfolder if the public folder mailbox database is secondary

Hi there,

on our exchange 2013 cu9 server we have the following problem:

When a user wants to create a new subfolder within a public folder structure the error "cannot create folder" appears.

This only happends in Outlook (2013). When I use the exchange admin center it works.

This problem only appears if the folder belongs to mailbox which is a secondary mailbox.

I can move the public folder to the primary mailbox database using a public folder move request. Then it works.So my question is: What is wrong there ?

The access rights are set to owner.

Thank You for a tip.

Greetings, Andy