That is odd.
When I check apple.com via the local DNS (a peplink router) and via 8.8.8.8 I get the same non-answer:
~ % dig apple.dot.com
; <<>> DiG 9.10.6 <<>> apple.dot.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 23254
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;apple.dot.com. IN A
;; AUTHORITY SECTION:
dot.com. 3600 IN SOA hera.ns.cloudflare.com. dns.cloudflare.com. 2034526707 10000 2400 604800 3600
;; Query time: 2 msec
;; SERVER: 192.168.10.1#53(192.168.10.1)
;; WHEN: Tue Feb 23 21:11:50 PST 2021
;; MSG SIZE rcvd: 101
~ % dig apple.dot.com @8.8.8.8
; <<>> DiG 9.10.6 <<>> apple.dot.com @8.8.8.8
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 27058
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;apple.dot.com. IN A
;; AUTHORITY SECTION:
dot.com. 1799 IN SOA hera.ns.cloudflare.com. dns.cloudflare.com. 2034526707 10000 2400 604800 3600
;; Query time: 135 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Tue Feb 23 21:12:36 PST 2021
;; MSG SIZE rcvd: 101
So I am puzzled.
Might your local response be an old cache entry somewhere?
When I perform an MX check I get solid answers (as one would expect):
~ % dig -t mx apple.com
; <<>> DiG 9.10.6 <<>> -t mx apple.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 26799
;; flags: qr rd ra; QUERY: 1, ANSWER: 11, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;apple.com. IN MX
;; ANSWER SECTION:
apple.com. 3600 IN MX 10 rn-mailsvcp-ppex-lapp45.apple.com.
apple.com. 3600 IN MX 10 rn-mailsvcp-ppex-lapp44.apple.com.
apple.com. 3600 IN MX 10 rn-mailsvcp-ppex-lapp35.apple.com.
apple.com. 3600 IN MX 10 rn-mailsvcp-ppex-lapp34.apple.com.
apple.com. 3600 IN MX 10 rn-mailsvcp-ppex-lapp25.apple.com.
apple.com. 3600 IN MX 10 rn-mailsvcp-ppex-lapp24.apple.com.
apple.com. 3600 IN MX 10 rn-mailsvcp-ppex-lapp15.apple.com.
apple.com. 3600 IN MX 10 rn-mailsvcp-ppex-lapp14.apple.com.
apple.com. 3600 IN MX 10 ma1-aaemail-dr-lapp03.apple.com.
apple.com. 3600 IN MX 10 ma1-aaemail-dr-lapp02.apple.com.
apple.com. 3600 IN MX 10 ma1-aaemail-dr-lapp01.apple.com.
;; Query time: 69 msec
;; SERVER: 192.168.10.1#53(192.168.10.1)
;; WHEN: Tue Feb 23 21:18:26 PST 2021
;; MSG SIZE rcvd: 472
In any way, the issue seems to be broader than your local router.
Z