Apex domains cannot have CNAME records.
Question and response
Question
dig jakob.dimaster.ch. NS
Answer
jakob.dimaster.ch. 2 NS ns2.dimastersoftware.ch.
jakob.dimaster.ch. 2 NS ns1.dimastersoftware.ch.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0