Apex domains cannot have CNAME records.
Question and response
Question
dig myecommercedns.com. NS
Answer
myecommercedns.com. 5 NS edns99.ultradns.com.
myecommercedns.com. 5 NS edns99.ultradns.net.
myecommercedns.com. 5 NS edns99.ultradns.org.
myecommercedns.com. 5 NS edns99.ultradns.biz.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0