Apex domains cannot have CNAME records.
Question and response
Question
dig 100hwl.com. NS
Answer
100hwl.com. 5 NS ns-1964.awsdns-53.co.uk.
100hwl.com. 5 NS ns-1800.awsdns-33.co.uk.
100hwl.com. 5 NS ns-453.awsdns-56.com.
100hwl.com. 5 NS ns-1846.awsdns-38.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0