Apex domains cannot have CNAME records.
Question and response
Question
dig slmccthv.com. NS
Answer
slmccthv.com. 5 NS ns-463.awsdns-57.com.
slmccthv.com. 5 NS ns-1374.awsdns-43.org.
slmccthv.com. 5 NS ns-362.awsdns-45.com.
slmccthv.com. 5 NS ns-868.awsdns-44.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0