Outlook prompts for credentials when opening Public Folders

Hi,

installed Exchange server CU23, and since then I keep getting a pop up title Windows Security when opening Public Folders.
I can retype my password, click on Remember my credentials, click OK and the same window pops up.
If I click CANCEL, "The set of folders cannot be opened" will appear.
It worked without problems with Exchange 2013 CU21.
Can you help me, please ?

System info: (all fully updated)
Windows Server 2012 R2
Exchange Server 2013 CU23
Outlook 2013 32-bit