Apex domains cannot have CNAME records.
Question and response
Question
dig howtoplayxblackjack.org. NS
Answer
howtoplayxblackjack.org. 3 NS ns-1617.awsdns-10.co.uk.
howtoplayxblackjack.org. 3 NS ns-378.awsdns-47.com.
howtoplayxblackjack.org. 3 NS ns-1097.awsdns-09.org.
howtoplayxblackjack.org. 3 NS ns-1179.awsdns-19.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0