Apex domains cannot have CNAME records.
Question and response
Question
dig gigilist.com. NS
Answer
gigilist.com. 5 NS ads4233057.earth.orderbox-dns.com.
gigilist.com. 5 NS ads4233057.mercury.orderbox-dns.com.
gigilist.com. 5 NS ads4233057.mars.orderbox-dns.com.
gigilist.com. 5 NS ads4233057.venus.orderbox-dns.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0