Apex domains cannot have CNAME records.
Question and response
Question
dig d2wppijibib1sf.cloudfront.net. NS
Answer
d2wppijibib1sf.cloudfront.net. 5 NS ns-392.awsdns-49.com.
d2wppijibib1sf.cloudfront.net. 5 NS ns-1331.awsdns-38.org.
d2wppijibib1sf.cloudfront.net. 5 NS ns-929.awsdns-52.net.
d2wppijibib1sf.cloudfront.net. 5 NS ns-1557.awsdns-02.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0