Apex domains cannot have CNAME records.
Question and response
Question
dig hzmo.ch. NS
Answer
hzmo.ch. 5 NS ns2.hzmo.ch.
hzmo.ch. 5 NS ns1.hzmo.ch.
Authority
The response has no authority records.
Additional
ns1.hzmo.ch. 5 A 46.232.178.6
ns2.hzmo.ch. 5 A 46.232.178.6
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0