Apex domains cannot have CNAME records.
Question and response
Question
dig thundernetwork.org. NS
Answer
thundernetwork.org. 5 NS kipp.ns.cloudflare.com.
thundernetwork.org. 5 NS jean.ns.cloudflare.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0