network unreachable resolving ‘./NS/IN’ or ‘./DNSKEY/IN’

While checking named status on Oracle Linux, the following warnings occur:

# systemctl status named
..
.
May 17 20:40:59 HOSTNAME named[8468]: network unreachable resolving './NS/IN': 2001:500:1::53#53
May 17 20:40:59 HOSTNAME named[8468]: network unreachable resolving './DNSKEY/IN': 2001:500:2d::d#53
..
.