Issue with SRV record for VOIP communication (missing SOA record)

Hi,

However, my VOIP box is using this to logon, using NextDNS it fails, using other public DNS it works as expected.

manual testing seems to work:

pi@raspberrypi:~ $ dig srv _sip._udp.tel.t-online.de

; <<>> DiG 9.11.5-P4-5.1+deb10u8-Raspbian <<>> srv _sip._udp.tel.t-online.de
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 11266
;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;_sip._udp.tel.t-online.de.     IN      SRV

;; ANSWER SECTION:
_sip._udp.tel.t-online.de. 3341 IN SRV 30 0 5060 h2-epp-110.edns.t-ipnet.de.
_sip._udp.tel.t-online.de. 3341 IN SRV 20 0 5060 d-epp-110.edns.t-ipnet.de.
_sip._udp.tel.t-online.de. 3341 IN SRV 10 0 5060 b-epp-110.edns.t-ipnet.de.

;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Mon Dec 05 09:45:44 CET 2022
;; MSG SIZE  rcvd: 190

And resulting in same as other DNS

pi@raspberrypi:~ $ dig srv _sip._udp.tel.t-online.de @1.1.1.1

; <<>> DiG 9.11.5-P4-5.1+deb10u8-Raspbian <<>> srv _sip._udp.tel.t-online.de @1.1.1.1
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 2201
;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;_sip._udp.tel.t-online.de.     IN      SRV

;; ANSWER SECTION:
_sip._udp.tel.t-online.de. 401 IN SRV 10 0 5060 s-epp-100.edns.t-ipnet.de.
_sip._udp.tel.t-online.de. 401 IN SRV 30 0 5060 h2-epp-110.edns.t-ipnet.de.
_sip._udp.tel.t-online.de. 401 IN SRV 20 0 5060 d-epp-110.edns.t-ipnet.de.

;; Query time: 12 msec
;; SERVER: 1.1.1.1#53(1.1.1.1)
;; WHEN: Mon Dec 05 10:00:13 CET 2022
;; MSG SIZE  rcvd: 190

When I look deeper, I see the following difference:

NextDNS:

pi@raspberrypi:~ $ dig f-eph-754.edns.t-ipnet.de

; <<>> DiG 9.11.5-P4-5.1+deb10u8-Raspbian <<>> f-eph-754.edns.t-ipnet.de
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 41540
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;f-eph-754.edns.t-ipnet.de.     IN      A

;; Query time: 11 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Mon Dec 05 10:34:21 CET 2022
;; MSG SIZE  rcvd: 54

Cloudflare (Google is the same):

pi@raspberrypi:~ $ dig f-eph-754.edns.t-ipnet.de @1.1.1.1

; <<>> DiG 9.11.5-P4-5.1+deb10u8-Raspbian <<>> f-eph-754.edns.t-ipnet.de @1.1.1.1
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 9680
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;f-eph-754.edns.t-ipnet.de.     IN      A

;; AUTHORITY SECTION:
edns.t-ipnet.de. 3500 IN SOA ns1.edns.t-ipnet.de. hostmaster.t-ipnet.net. 2022112501 1800 900 7257600 3600

;; Query time: 13 msec
;; SERVER: 1.1.1.1#53(1.1.1.1)
;; WHEN: Mon Dec 05 10:35:18 CET 2022
;; MSG SIZE  rcvd: 116