Apex domains cannot have CNAME records.
Question and response
Question
dig flexitrol.com. NS
Answer
flexitrol.com. 5 NS ns-111.awsdns-13.com.
flexitrol.com. 5 NS ns-1678.awsdns-17.co.uk.
flexitrol.com. 5 NS ns-2.awsdns-00.com.
flexitrol.com. 5 NS ns-952.awsdns-55.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0