Apex domains cannot have CNAME records.
Question and response
Question
dig prosodie.net. NS
Answer
prosodie.net. 5 NS ns-990.awsdns-59.net.
prosodie.net. 5 NS ns-466.awsdns-58.com.
prosodie.net. 5 NS ns-1571.awsdns-04.co.uk.
prosodie.net. 5 NS ns-1178.awsdns-19.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0