Apex domains cannot have CNAME records.
Question and response
Question
dig ceresplant.com. NS
Answer
ceresplant.com. 5 NS ns-632.awsdns-15.net.
ceresplant.com. 5 NS ns-275.awsdns-34.com.
ceresplant.com. 5 NS ns-145.awsdns-18.com.
ceresplant.com. 5 NS ns-350.awsdns-43.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0