Apex domains cannot have CNAME records.
Question and response
Question
dig initiative-ringelblume.org. NS
Answer
initiative-ringelblume.org. 5 NS ns-941.awsdns-53.net.
initiative-ringelblume.org. 5 NS ns-1599.awsdns-07.co.uk.
initiative-ringelblume.org. 5 NS ns-473.awsdns-59.com.
initiative-ringelblume.org. 5 NS ns-524.awsdns-01.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0