Quad9 return incorrect fly.dev ip address

I try to dig and found Quad9 return incorrect IP for my fly.dev

Cloudflare - 37.16.19.x
Google - 37.16.19.x
Quad9 - 168.220.89.x

Look like DNS propagation delay on Quad9, Is this known issue on fly.io ?

I haven’t seen anything on our end that would indicate that there’s an issue with Quad9 DNS updating records.

How long have you been seeing this for? Is this app running still? Taking a look at what seems like the running app of yours in question, it was resolving to the 37.16.19.x address a few minutes after you posted:

;; ANSWER SECTION:
[xxx].fly.dev. 3600   IN      A       37.16.19.[xxx]

;; Query time: 33 msec
;; SERVER: 9.9.9.9#53(9.9.9.9) (UDP)
;; WHEN: Fri Aug 26 14:17:39 EDT 2022

Please let us know if this is a persistent issue-- we’re always happy to dig into whatever problems you run into!

I can see it for 10 minutes, I try to dig 9.9.9.9 from time to time until see it up-to-date with other DNS