Apex domains cannot have CNAME records.
Question and response
Question
dig hhv-gallery.com. NS
Answer
hhv-gallery.com. 5 NS ns-1690.awsdns-19.co.uk.
hhv-gallery.com. 5 NS ns-1564.awsdns-03.co.uk.
hhv-gallery.com. 5 NS ns-1015.awsdns-62.net.
hhv-gallery.com. 5 NS ns-1412.awsdns-48.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0