Exchange Hybrid Best Practises about autodiscover

Hey guys,
I really have been looking forward to an answer here. Anybody an idea?

In the meantime we found some further gaps. So we have the two servers in the DAG (EX2013) and the one additional server for the hybrid (EX2016). All mailboxes are located on the DAG. When the users on the client remove the cached mode, the are not able to open the addressbook. So it's the online addressbook, not the offline addressbook.
In advance I have now added the correct virtual directories, so the are all now the same for the 3 Exchange servers.

But it is still not working. So for testing I have moved a productive mailbox to the Hybrid server and here it is all working for the user.

So what can be the issue here? Just the version differences between EX2013 and EX2016.

Kind regards,

woelki