Apex domains cannot have CNAME records.
Question and response
Question
dig medalliafederal.com. NS
Answer
medalliafederal.com. 2 NS ns-1904.awsdns-46.co.uk.
medalliafederal.com. 2 NS ns-308.awsdns-38.com.
medalliafederal.com. 2 NS ns-528.awsdns-02.net.
medalliafederal.com. 2 NS ns-1113.awsdns-11.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0