Apex domains cannot have CNAME records.
Question and response
Question
dig qualityunit.com. NS
Answer
qualityunit.com. 4 NS ns-538.awsdns-03.net.
qualityunit.com. 4 NS ns-1518.awsdns-61.org.
qualityunit.com. 4 NS ns-1927.awsdns-48.co.uk.
qualityunit.com. 4 NS ns-424.awsdns-53.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0