Apex domains cannot have CNAME records.
Question and response
Question
dig redcloud.ch. NS
Answer
redcloud.ch. 5 NS customerdns002.redcloud.ch.
redcloud.ch. 5 NS customerdns001.redcloud.ch.
redcloud.ch. 5 NS customerdns003.redcloud.ch.
Authority
The response has no authority records.
Additional
customerdns001.redcloud.ch. 5 A 194.50.187.134
customerdns002.redcloud.ch. 5 A 194.0.182.1
customerdns003.redcloud.ch. 5 A 193.227.117.124
customerdns001.redcloud.ch. 5 AAAA 2a04:2b00:14cc:0:0:0:0:4
customerdns002.redcloud.ch. 5 AAAA 2a04:2b00:14dd:0:0:0:0:4
customerdns003.redcloud.ch. 5 AAAA 2a04:2b00:14ee:0:0:0:0:4
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0