Unbound DNS resolver returns with SERVFAIL in ubuntu:latest

Hi!

I’m using unbound DNS resolver in a ubuntu container for my LAN requests. I’ve noticed, that ubuntu:latest is no longer work. The last image which is working ubuntu:bionic.
The issue is, that the unbound service is not able to handle upstream requests, returns with

** server can’t find index.hu: SERVFAIL

The local requests are still working:

nslookup socialtrade.biz dns-server
[ output omitted ]
Name: socialtrade.biz # this is an advertising site
Address: 0.0.0.0

Interesting: With debian:latest it does provide the same issue.

Here you can find the Dockerfile, configs, and the command with which I’m running:
https://github.com/kzl86/dns_server

I’m looking for a solution why this stopped working.

Thank you