Exchange 2016 Problem for new mailboxes or new accounts after CU20 with hafnium patch

I've the same problem of this topic

https://techcommunity.microsoft.com/t5/exchange/an-error-occurred-while-trying-to-get-the-address-book-server/m-p/2198330

Isn't it that someone has a solution? It's very frustrating. 

All the joined account are working but the new ones or if i try to add an existing one i receive an error about cryptography or the account join goes right, but on the first outlook open there's an "impossibile to find exchange server of mailbox group, be sure the server is online or connected".

Autodiscover is working, certifcate is new and trusted by a 3rd party authority. It seems really that after CU20 nothing works like before.

Need Help.

thank you.