Apex domains cannot have CNAME records.
Question and response
Question
dig dns.as8607.net. NS
Answer
dns.as8607.net. 4 NS ns-558.awsdns-05.net.
dns.as8607.net. 4 NS ns-396.awsdns-49.com.
dns.as8607.net. 4 NS ns-1862.awsdns-40.co.uk.
dns.as8607.net. 4 NS ns-1461.awsdns-54.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0