Apex domains cannot have CNAME records.
Question and response
Question
dig topo-triton.com. NS
Answer
topo-triton.com. 2 NS ns-112.awsdns-14.com.
topo-triton.com. 2 NS ns-872.awsdns-45.net.
topo-triton.com. 2 NS ns-652.awsdns-17.net.
topo-triton.com. 2 NS ns-1901.awsdns-45.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0