DNS response policy zone

I am trying to add a response policy zone to override some DNS entries with their local equivalents.
It seems to have wroked at first, but for some reason (after some time) bind “forgets” the response policy zone entries and returns the public IP again instead of the internal one.
Here’s how I did it: https://blog.lordvan.com/blog/how-to-add-a-dns-responce-policy-zone-to-univention-corporate-server-ucs/
Did i make a mistake somewhere? Any help would be appreciated. – and even more so would be an easier way to do this without editing named.conf.local :wink: