OK, now I am even more interested. dig doesn’t return an A record:

$ dig glauca.digital a

; <<>> DiG 9.20.27 <<>> glauca.digital a
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 11516
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;glauca.digital.                        IN      A

;; AUTHORITY SECTION:
glauca.digital.         3600    IN      SOA     ns1.as207960.net. 2bd17d47fafc43aa9be298a1cdfbd0ee.dns.glauca.digital. 1791925047 86400 3600 86400 3600

Somehow, it does work in a browser. I tried different DNS servers as well (including NextDNS which I use in a browser), none returns an A record (or AAAA). So, naturally, I am curios what IP the browser uses. Since it clearly works, I tried ping just so that I could see the resulting IP, and figure out where it’s coming from.

$ ping glauca.digital
ping: glauca.digital: No address associated with hostname

Great. That makes absolutely no sense at all. Where is Firefox getting the information from?
So I went to about:networking DNS tab. The address field is empty. I am just typing this as I test. It’s just cache in my browser.

I guess that would answer on reliability question. At least their nameservers still resolve to IP.