cock.li resolves perfectly fine on Firefox with Cloudflare DoH.
Can you run dig @1.1.1.1 cock.li just in case?
; (1 server found) ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 49352 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 1232 ; EDE: 0 (Other): (time limit exceeded) ;; QUESTION SECTION: ;cock.li. IN A ;; Query time: 115 msec ;; SERVER: 1.1.1.1#53(1.1.1.1) (UDP)
; (1 server found) ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 21996 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 512 ;; QUESTION SECTION: ;cock.li. IN A ;; ANSWER SECTION: cock.li. 300 IN A 193.239.85.202 ;; Query time: 159 msec ;; SERVER: 8.8.8.8#53(8.8.8.8) (UDP)