Apex domains cannot have CNAME records.
Question and response
Question
dig smithsport.net. NS
Answer
smithsport.net. 3 NS ns-560.awsdns-06.net.
smithsport.net. 3 NS ns-1776.awsdns-30.co.uk.
smithsport.net. 3 NS ns-979.awsdns-58.net.
smithsport.net. 3 NS ns-1981.awsdns-55.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0