Hello,
 
We are planning to update our Exchange setup to CU9. So, is Exchange 2013 CU9 supported with Hosting Controller?
 
Tom

We applied CU9 on one of our HC9 server and it started to Exchange Connectivity issue. And I have contacted with support department and then they helped me out to fix the connectivity issue. 
 
I have tested it and CU9 is supported with Hosting Controller. After applied CU9 you will face the Exchange Connectivity issue which can be sorted out with the given KB article: 
 
Regards,
Clarke

@ Clarke I think you missed the kb article link :( .