Schannel error when try to download OAB

Hi to all.

I've following infrastructure:

2 DC with Win2012 r2 (1 of this with all FSMO role)

1 Exchange 2013 cu7 on Win2012 r2 with Wildcard Certificate

Clients Windows 7 and 10 with Outlook 2013 (all updates)

**********************

Problem:

For several weekstheclients, when the try to download OAB from Account Settings menu, received the following error :

0x80072F7d

and in event viewer :

Error Schannel ID 36887

Nome registro: System
Origine:       Schannel
Data:          17/03/2016 08:40:02
ID evento:     36887
Categoria attività:Nessuna
Livello:       Errore
Parole chiave:
Utente:        SYSTEM
Computer:      PCA.dominio.local
Descrizione:
Ricevuto avviso di errore irreversibile dall'endpoint remoto. Codice dell'avviso di errore irreversibile definito dal protocollo TLS: 80.
XML evento:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event"><System><Provider Name="Schannel" Guid="{1F678132-5938-4686-9FDC-C8FF68F15C85}" /><EventID>36887</EventID><Version>0</Version><Level>2</Level><Task>0</Task><Opcode>0</Opcode><Keywords>0x8000000000000000</Keywords><TimeCreated SystemTime="2016-03-17T07:40:02.884534400Z" /><EventRecordID>31106</EventRecordID><Correlation ActivityID="{3C32F3DE-7F83-0002-FCF3-323C837FD101}" /><Execution ProcessID="476" ThreadID="4984" /><Channel>System</Channel><Computer>PCA.dominio.local</Computer><Security UserID="S-1-5-18" /></System><EventData><Data Name="AlertDesc">80</Data></EventData></Event>

I've run this command in EMS:

Test-OutlookWebServices

and receive all SUCCESS

From clients i can access to OAB.xml file (the URL is present in Test Autodiscovery log)

Can someonehelp me to fix the problem?

Thank you for any suggestions and help.

(ps. sorry for my english)

/Mino