Apex domains cannot have CNAME records.
Question and response
Question
dig dkptfhtbc2i6q.cloudfront.net. NS
Answer
dkptfhtbc2i6q.cloudfront.net. 5 NS ns-702.awsdns-23.net.
dkptfhtbc2i6q.cloudfront.net. 5 NS ns-131.awsdns-16.com.
dkptfhtbc2i6q.cloudfront.net. 5 NS ns-1835.awsdns-37.co.uk.
dkptfhtbc2i6q.cloudfront.net. 5 NS ns-1047.awsdns-02.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0