Unbound DNS无法解析域名的原因排查求助

各位好，这是我之前问题的跟进求助。下面是我的/etc/unbound/unbound.conf配置文件内容：

# unbound.conf(5) config file for unbound(8).
server:
    directory: "/etc/unbound"
    username: "unbound"
    chroot: ""
    logfile: "/etc/unbound/unbound.log"
    pidfile: "/etc/unbound/unbound.pid"
    verbosity: 1
    # listen on all interfaces and answer queries from the local port 3000.
    interface: 0.0.0.0 
    interface: ::0
    port: 3000
    access-control: 10.0.0.0/8 allow
    #access-control: 2001:DB8::/64 allow

我已经启动了unbound.service服务，接着尝试通过本地的Unbound服务器解析域名，执行了这条命令：

root@DNS:/etc/unbound# dig example.com A @192.168.1.50 -p 3000

命令返回的结果如下：

; <<>> DiG 9.18.28-0ubuntu0.24.04.1-Ubuntu <<>> example.com A @192.168.1.50 -p 3000
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: REFUSED, id: 8367
...

现在查询返回了REFUSED状态，有没有大佬能帮我排查下原因呀？

备注：内容来源于stack exchange，提问作者Sun Bear