I have set up a WireGuard VPN server on the router. I used the generated .conf file, changing only the endpoint and DNS server.  I want to use my LAN DNS server, since it handles local single name machines. But the tunnel always uses Google's DNS server (8.8.8.8). I can use IP addresses and get access to those servers, but there are several apps the have been configured to use the single names. Here is my .conf file, with the endpoint and DNS server changed:

[Interface]
PrivateKey = xxx=
Address = 10.5.5.2/32
DNS = 192.168.1.100

[Peer]
PublicKey = xxx=
PresharedKey = xxx=
AllowedIPs = 0.0.0.0/0
Endpoint = <myname>
PersistentKeepalive = 25

Any help greatly appreciated.

TIA

ken