High latency for bind9 over wireguard

Question

I have a DNS home server running with bind9. To keep using my server outside my local network, I configured a VPN with wireguard.
With this command : time wget -O/dev/null https://debian.org, here are the latencies of the same request in two different network environments

Local network                    ---> 0,647s
Outside network (over wireguard) ---> 11,007s

If i make the test with an IP Address : time wget -O/dev/null https://128.31.0.62 --no-check-certificate :

Local network                    ---> 0,459s
Outside network (over wireguard) ---> 0,738s

I don't understand why the name resolution over wireguard is so slow.

Edit

As @mtak wrote in response, to test if the problem comes from the name resolution, we used the following commands : `time dig debian.org @1.2.3.4` where 1.2.3.4 is the IP of the bind server.

Local network   ---> 0,058s
Outside network ---> 0,036s

So if the problem isn't name resolution, what is it ?

Answer 1

Well, that was the resolv.conf file. The DNS server of the local network was above that of the external network. And as it says in the resolv.conf manual :

If there are multiple servers, the resolver library queries them in the order listed.

So It was the first DNS server query time that was causing the latency.