Apex domains cannot have CNAME records.
Question and response
Question
dig 89grad.ch. NS
Answer
89grad.ch. 5 NS dns01.89grad.ch.
89grad.ch. 5 NS dns00.89grad.ch.
Authority
The response has no authority records.
Additional
dns00.89grad.ch. 5 A 83.222.142.227
dns01.89grad.ch. 5 A 83.222.129.244
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0