[plug] Strange DNS issue for AU domains

[Alex]

I am no longer able to resolved AU domains and a little stuck with 
diagnosing the issue.

goldberry ~ # dig google.com.au

; <<>> DiG 9.16.41 <<>> google.com.au
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 14548
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
; COOKIE: f7c4f09b033fe6ff0100000065079ee2206067b69b541459 (good)
;; QUESTION SECTION:
;google.com.au.                 IN      A

;; Query time: 211 msec
;; SERVER: 192.168.0.3#53(192.168.0.3)
;; WHEN: Mon Sep 18 08:50:42 AWST 2023
;; MSG SIZE  rcvd: 70

While .com domains resolve just fine

goldberry ~ # dig google.com

; <<>> DiG 9.16.41 <<>> google.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 38334
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
; COOKIE: a9ea8850e0e3a21b0100000065079eedeaf9099608081f6c (good)
;; QUESTION SECTION:
;google.com.                    IN      A

;; ANSWER SECTION:
google.com.             169     IN      A       142.250.70.142

;; Query time: 0 msec
;; SERVER: 192.168.0.3#53(192.168.0.3)
;; WHEN: Mon Sep 18 08:50:53 AWST 2023
;; MSG SIZE  rcvd: 83


Using dig +trace I get the following error:

couldn't get address for 't.au': failure
couldn't get address for 'c.au': failure
couldn't get address for 'd.au': failure
couldn't get address for 'q.au': failure
couldn't get address for 'r.au': failure
couldn't get address for 's.au': failure
dig: couldn't get address for 't.au': no more

The strange thing is that even when specifying other public DNS servers 
using @8.8.8.8 or @1.1.1.1 it still shows the same errors.

As it happens the issues just resolved itself a minute ago, but it seems 
a little strange.

Any pointers or thoughts what might have happened ?