Apex domains cannot have CNAME records.
Question and response
Question
dig acemip.com. NS
Answer
acemip.com. 2 NS ns-868.awsdns-44.net.
acemip.com. 2 NS ns-1646.awsdns-13.co.uk.
acemip.com. 2 NS ns-328.awsdns-41.com.
acemip.com. 2 NS ns-620.awsdns-13.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0