Can't resolve Domain Controller when adding AD Auth Service

[#1]

When adding an Active Directory domain controller by FQDN to the "Active Directory authentication service" wizard, I get: cannot resolve FQDN addc01.lab.local. If I add it by IP (can't do TLS), it will connect and work. 

However, both the IB appliance and AD integrated DNS can resolve that hostname. What do I have to configure so that the Authentication Service Groups can resolve a FQDN within my network?

[#2]

I'd like to add that SSHing into the IB and doing a ping to the FQDN of the domain controller DOES work. So at least some parts of NIOS have working name resolution, just not the auth service configuration window. 

[#3]

We got the same Problem.
We try to Add Our AD Domain Server as Authentication Server Group and also get:

Cannot Resolv FQDN for the Domain Controller.

Infoblox is our Main DNS for this Domain, the DCs can resolved without any Problems.

Do you found a solution for this Problem ?

Kind Regards

Markus