DNS turning wrong

Hi,

I installed yunohost a few months ago. Everything went fine. I chose agdc.noho.st as my domain name.
A few days ago, I noticed I sometimes can not connect to my server. The normal IP address should be 87.231.146.146, but when I tried to find which IP agdc.noho.st refers to, dig gave me something like 213.223.80.239 (I did not wrote the IP down though).

I rebooted my server. Some time later, dig agdc.noho.st gave me again my ip. Fine. But again, today, I found agdc.noho.st to be 213.223.80.239 (see below the whole output from dig).

I found in /etc/cron.d/yunohost-dyndns that yunohost dyndns update would probably fix this again. It did (see below the output of dig), at least on my server (on a client machine, agdc.noho.st still points to 213.223.80.239, I guess it needs some time to get the new address).

I was wondering what happened and whether it will happen again.
Could it be that somebody else chose the very same name and that we race for it?

Yours,

Judicaël.

What “dig” says when I can not reach my server:

# dig agdc.noho.st

; <<>> DiG 9.10.3-P4-Debian <<>> agdc.noho.st
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 23691
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4000
;; QUESTION SECTION:
;agdc.noho.st. IN A

;; ANSWER SECTION:
agdc.noho.st. 353 IN A 213.223.80.239

;; Query time: 15 msec
;; SERVER: 89.2.0.1#53(89.2.0.1)
;; WHEN: Fri Nov 03 11:09:30 CET 2017
;; MSG SIZE rcvd: 57

And after a «yunohost dyndns update»:

# dig agdc.noho.st

; <<>> DiG 9.9.5-9+deb8u14-Debian <<>> agdc.noho.st
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 44706
;; flags: qr aa rd ra ad; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;agdc.noho.st. IN A

;; ANSWER SECTION:
agdc.noho.st. 0 IN A 87.231.146.146

;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Fri Nov 03 11:35:18 CET 2017
;; MSG SIZE rcvd: 46