Apex domains cannot have CNAME records.
Question and response
Question
dig hyvor-relay.com. NS
Answer
hyvor-relay.com. 5 NS fay.ns.cloudflare.com.
hyvor-relay.com. 5 NS newt.ns.cloudflare.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0