Apex domains cannot have CNAME records.
Question and response
Question
dig dmnodes.net. NS
Answer
dmnodes.net. 3 NS mary.ns.cloudflare.com.
dmnodes.net. 3 NS mark.ns.cloudflare.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0