Apex domains cannot have CNAME records.
Question and response
Question
dig nine.ch. NS
Answer
nine.ch. 5 NS ns0152.secondary.cloudflare.com.
nine.ch. 5 NS 0ns1.nine.ch.
nine.ch. 5 NS ns0048.secondary.cloudflare.com.
nine.ch. 5 NS 0ns2.nine.ch.
nine.ch. 5 NS 0ns3.nine.ch.
Authority
The response has no authority records.
Additional
0ns1.nine.ch. 5 A 217.150.241.4
0ns2.nine.ch. 5 A 217.150.242.20
0ns3.nine.ch. 5 A 193.17.85.120
0ns1.nine.ch. 5 AAAA 2a02:419:1002:0:0:0:0:4
0ns2.nine.ch. 5 AAAA 2a02:418:4005:0:0:0:0:20
0ns3.nine.ch. 5 AAAA 2001:67c:2f98:3:0:0:0:3
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0