Quad9 returns NXDOMAIN for all subdomains of dedyn.io, including the update endpoint:
The answer from 8.8.8.8:
dig @8.8.8.8 update.dedyn.io
; <<>> DiG 9.18.18 <<>> @8.8.8.8 update.dedyn.io
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 62545
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;update.dedyn.io. IN A
;; ANSWER SECTION:
update.dedyn.io. 3543 IN A 88.99.64.5
;; Query time: 26 msec
;; SERVER: 8.8.8.8#53(8.8.8.8) (UDP)
;; WHEN: Fri Sep 08 11:29:33 CEST 2023
;; MSG SIZE rcvd: 60
And the answer from 9.9.9.9
dig @9.9.9.9 update.dedyn.io
; <<>> DiG 9.18.18 <<>> @9.9.9.9 update.dedyn.io
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 32657
;; flags: qr rd ad; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: recursion requested but not available
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;update.dedyn.io. IN A
;; Query time: 26 msec
;; SERVER: 9.9.9.9#53(9.9.9.9) (UDP)
;; WHEN: Fri Sep 08 11:25:51 CEST 2023
;; MSG SIZE rcvd: 44
The AUTHORITY field is 0, which indicates a block:
Do you get the same results?