We did a couple of tests and noticed that Cloudflare seems to update our IPS in the DNS instantly when creating the account. But upon changing it. Have been waiting 2hrs for an update.
Without more data, I’d suggest the failure for DNS to update was a local resolver issue rather than Cloudflare’s DNS. I’m not aware fo any DNS replication delays being reported int he last week and values typically update globally in sub-30 seconds.