Apex domains cannot have CNAME records.
Question and response
Question
dig dataphone.ch. NS
Answer
dataphone.ch. 5 NS ns60.domaincontrol.com.
dataphone.ch. 5 NS ns59.domaincontrol.com.
Authority
The response has no authority records.
Additional
ns59.domaincontrol.com. 2 A 97.74.100.31
ns60.domaincontrol.com. 2 A 173.201.68.31
ns59.domaincontrol.com. 2 AAAA 2603:5:2143:0:0:0:0:1f
ns60.domaincontrol.com. 2 AAAA 2603:5:2243:0:0:0:0:1f
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0