Apex domains cannot have CNAME records.
Question and response
Question
dig nathan-castle.org. NS
Answer
nathan-castle.org. 5 NS ns-1125.awsdns-12.org.
nathan-castle.org. 5 NS ns-1435.awsdns-51.org.
nathan-castle.org. 5 NS ns-597.awsdns-10.net.
nathan-castle.org. 5 NS ns-1154.awsdns-16.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0