system nspawned container does not resolve certain dns

Question

i have system nspawned container(ubuntu) running on a rhel host. the host has a nameserver 168.***, and container has a systemd-resolved nameserver 127.0.0.53. The container's nameserver resolves most of the dns i tried, except 1, which can be resolved by host nameserver. for example:

on the container:

nslookup www.xyz.com
Server:     127.0.0.53
Address:    127.0.0.53#53

** server can't find proxy.conexus.svc.local: SERVFAIL

but on host:

nslookup www.xyz.com
Server:     168.*.*.*
Address:    168.*.*.*#53

Non-authoritative answer:
Name:   www.xyz.com
Address: *.*.*.*

The nameserver on container can resolve almost any other dns i tried, except for this one.

How will i be able to resolve it with the container's nameserver? Any help will be apprecaited!