Apex domains cannot have CNAME records.
Question and response
Question
dig bw-werbeartikel.at. NS
Answer
bw-werbeartikel.at. 5 NS jonah.ns.cloudflare.com.
bw-werbeartikel.at. 5 NS athena.ns.cloudflare.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0