Apex domains cannot have CNAME records.
Question and response
Question
dig sseamax.com. NS
Answer
sseamax.com. 5 NS ns-374.awsdns-46.com.
sseamax.com. 5 NS ns-1885.awsdns-43.co.uk.
sseamax.com. 5 NS ns-1607.awsdns-08.co.uk.
sseamax.com. 5 NS ns-881.awsdns-46.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0