I have set up successful a VPN server en my mobile device can connect to it

I can also ping local addresses (192.168.0..0  ) and reach my router webpage, and i can even browse over Internet.

So what is the problem ?? i want to use an internal DNS server directly connect to the AX20 router (so the same subnet as My NAS 192.168.0.0)

ik can resove the web interface from my phone to the NAS useing the local adress (192,168.0.208)  on the NAS runs a docker wit PIhole on the same adres as the NAS.

when i at home and confure the DNS tot the adress of the NAS/Pihole ererything works, Pihole does the job.

But over VPN Internet works but with adds .... so how can ik configure it so that. over the VPN goes to my own DNS ?

i think the main problem is that i have no FULL tunnel, hoe can i check it on a simulation on my Mac, with no wifi to the router but to a hotspot connection en set up a VPN ?

or do i need a extra routing table entry in the router to tell where it can find the DNS server inside my network ?

on the router i try both modes "Internet an home" and "Home network" 

here is the openvpn config  :

client
dev tun
proto udp
float
nobind
cipher AES-128-CBC
comp-lzo adaptive
resolv-retry infinite
remote-cert-tls server
persist-key
persist-tun
remote xxx.xxx.xxx.xxx 1194
<ca>
-----BEGIN CERTIFICATE-----