Apex domains cannot have CNAME records.
Question and response
Question
dig fede1.medalliafederal.com. NS
Answer
fede1.medalliafederal.com. 5 NS ns-1879.awsdns-42.co.uk.
fede1.medalliafederal.com. 5 NS ns-367.awsdns-45.com.
fede1.medalliafederal.com. 5 NS ns-516.awsdns-00.net.
fede1.medalliafederal.com. 5 NS ns-1041.awsdns-02.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0