Apex domains cannot have CNAME records.
Question and response
Question
dig claudeprudhomme.com. NS
Answer
claudeprudhomme.com. 5 NS ns-180.awsdns-22.com.
claudeprudhomme.com. 5 NS ns-711.awsdns-24.net.
claudeprudhomme.com. 5 NS ns-953.awsdns-55.net.
claudeprudhomme.com. 5 NS ns-1699.awsdns-20.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0