I'm using an ACC instance on Amazon EC2. A few days ago, I received an email warning that the cluster-host was degraded and would be taken down, so I should stop/start my instance to move it to another cluster. Of course, this resulted in the ACC having a different public IP and public FQDN.
No problem, as I already had created a CNAME entry in public DNS for acc3.mydomain.com. I updated that with the new Amazon FQDN, but still had no joy in my Astaro, even today, several days after the change! I realized that I hadn't changed the entry in my internal DNS (see DNS Best Practice). Once I had changed that and flushed the caches both there and on the Astaro, ping from 'Support >> Tools' gave the correct result for acc3.mydomain.com.
However, nothing changed for the DNS host definition. I opened in and saved it - still the old address.
Finally, I created a new DNS Host definition using acc3.mydomain.com. As soon as confd finished displaying the new definition, I saw that the old definition had updated. I suspect that this behavior has existed for awhile.
Cheers - Bob