Apex domains cannot have CNAME records.
Question and response
Question
dig arthur3259sh.com. NS
Answer
arthur3259sh.com. 5 NS ns-1538.awsdns-00.co.uk.
arthur3259sh.com. 5 NS ns-1637.awsdns-12.co.uk.
arthur3259sh.com. 5 NS ns-1911.awsdns-46.co.uk.
arthur3259sh.com. 5 NS ns-332.awsdns-41.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0