So I am stumbling a little here. I have a Synology DS 1515+ I want to use as local DNS then forward out for other queries. Seems pretty straight forward setup. But doesn't seem to work like I thought.

This is probably not the answer you are looking for but ... You should be using your second domain controller as your secondary DNS server. If you don't have 2 domain controllers (or more), do not ...

If you're new to DNS, the easiest way to understand it is to compare it to a phone book. DNS is the phone book of the internet, except we don’t get to choose what number gets listed. Most of us let ...