Apex domains cannot have CNAME records.
Question and response
Question
dig computerfarm.ch. NS
Answer
computerfarm.ch. 5 NS omni.computerfarm.ch.
computerfarm.ch. 5 NS postino.computerfarm.ch.
computerfarm.ch. 5 NS monday.computerfarm.ch.
Authority
The response has no authority records.
Additional
omni.computerfarm.ch. 5 A 46.14.184.195
monday.computerfarm.ch. 5 A 78.155.24.134
postino.computerfarm.ch. 5 A 46.14.184.196
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0