@flashVenom 

My LAN 1 interface on my Synology DSM has a DNS of, let's say 192.168.17.20. This happens to be the IP of the Synology DSM, itself. I also have another DNS server on my network, on Windows Server 2016 at let's say 192.168.17.10. I think my issue regarding the original post was that my Domain/LDAP settings had the DNS server set to 192.168.17.10 which seems to confilect with the LAN 1 DNS which I had originally set to 192.168.17.10.

On my previous post due, to wanting to resolve local IPs by hostname over VPN, I duplicated and linked my DNS servers so now I can use 192.168.17.20 on my LAN 1 interface to avoid conflict with the DNS of the Domain/LDAP and my static IP on my LAN 1 interface doesn't change after reboot. It may also behoove you to make sure you don't have multiple DHCP servers on net. I know Synology DSM has DHCP server capabilities, also.

BTW, I don't think any of this would be an issue using a public outside DNS (ie. Google's 8.8.8.8 or Cloud Flare's 1.1.1.1). But the way I see it, if you're even using these forums, you're probably trying to take advantage of the awesome features in your Synology DSM so using the ppublic DNS servers probably isn't what you're looking to do.

I hope this helps.