Apex domains cannot have CNAME records.
Question and response
Question
dig jzckvmdcqj.acm-validations.aws. NS
Answer
jzckvmdcqj.acm-validations.aws. 5 NS ns-896.awsdns-48.net.
jzckvmdcqj.acm-validations.aws. 5 NS ns-1703.awsdns-20.co.uk.
jzckvmdcqj.acm-validations.aws. 5 NS ns-346.awsdns-43.com.
jzckvmdcqj.acm-validations.aws. 5 NS ns-1524.awsdns-62.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0