Apex domains cannot have CNAME records.
Question and response
Question
dig srv01.neotrend.ch. NS
Answer
srv01.neotrend.ch. 5 NS dns2.neotrend.ch.
srv01.neotrend.ch. 5 NS dns1.neotrend.ch.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0