Apex domains cannot have CNAME records.
Question and response
Question
dig hleath.com. NS
Answer
hleath.com. 5 NS ns-1415.awsdns-48.org.
hleath.com. 5 NS ns-1717.awsdns-22.co.uk.
hleath.com. 5 NS ns-1909.awsdns-46.co.uk.
hleath.com. 5 NS ns-854.awsdns-42.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0