Apex domains cannot have CNAME records.
Question and response
Question
dig parkettmueller.com. NS
Answer
parkettmueller.com. 5 NS ns-988.awsdns-59.net.
parkettmueller.com. 5 NS ns-1809.awsdns-34.co.uk.
parkettmueller.com. 5 NS ns-1817.awsdns-35.co.uk.
parkettmueller.com. 5 NS ns-747.awsdns-29.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0