Apex domains cannot have CNAME records.
Question and response
Question
dig rugbyworldmagazine.com. NS
Answer
rugbyworldmagazine.com. 5 NS ns2.rugbyworldmagazine.com.
rugbyworldmagazine.com. 5 NS ns1.rugbyworldmagazine.com.
Authority
The response has no authority records.
Additional
ns1.rugbyworldmagazine.com. 5 A 51.210.181.164
ns2.rugbyworldmagazine.com. 5 A 51.254.12.38
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0