Apex domains cannot have CNAME records.
Question and response
Question
dig hartofhighland.com. NS
Answer
hartofhighland.com. 5 NS ns-1902.awsdns-45.co.uk.
hartofhighland.com. 5 NS ns-370.awsdns-46.com.
hartofhighland.com. 5 NS ns-547.awsdns-04.net.
hartofhighland.com. 5 NS ns-792.awsdns-35.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0