Apex domains cannot have CNAME records.
Question and response
Question
dig zaacwoodhead.com. NS
Answer
zaacwoodhead.com. 3 NS ns-1548.awsdns-01.co.uk.
zaacwoodhead.com. 3 NS ns-1542.awsdns-00.co.uk.
zaacwoodhead.com. 3 NS ns-968.awsdns-57.net.
zaacwoodhead.com. 3 NS ns-1714.awsdns-22.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0