Apex domains cannot have CNAME records.
Question and response
Question
dig test-infra.ch. NS
Answer
test-infra.ch. 1 NS dns0.test-infra.ch.
test-infra.ch. 1 NS dns0.arcanite-infra.ch.
Authority
The response has no authority records.
Additional
dns0.test-infra.ch. 1 A 146.4.119.109
dns0.arcanite-infra.ch. 1 A 79.110.235.11
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0