CNAME not propagating consistently. Doesn't resolve at 1.1.1.1

[broad]

What is the name of the domain?

thebroad.org

What is the issue you’re encountering

Recently added CNAME resolves at some nameserver but not others.

What steps have you taken to resolve the issue?

Confirmed that proxy is NOT enabled.
Waited a day.
Flatten CNAME at apex is selected.

What feature, service or problem is this related to?

DNS records

What are the steps to reproduce the issue?

Check DNS Propagation Checker - Global DNS Testing Tool

[Laudian]

You have delegated the _domainkey subdomain to a different DNS server:

thebroad.org.           3600    IN      NS      kim.ns.cloudflare.com.
thebroad.org.           3600    IN      NS      hans.ns.cloudflare.com.
;; Received 106 bytes from 199.249.120.1#53(b2.org.afilias-nst.org) in 8 ms

_domainkey.thebroad.org. 300    IN      NS      ns-dkim.ondmarc.com.
;; Received 85 bytes from 2803:f800:50::6ca2:c07e#53(kim.ns.cloudflare.com) in 4 ms

Either delete the NS record or create your DKIM record in their DNS system.

[broad]

Thanks Laudian!