Apex domains cannot have CNAME records.
Question and response
Question
dig ascentis.com. NS
Answer
ascentis.com. 4 NS ns-666.awsdns-19.net.
ascentis.com. 4 NS ns-1910.awsdns-46.co.uk.
ascentis.com. 4 NS ns-210.awsdns-26.com.
ascentis.com. 4 NS ns-1079.awsdns-06.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0