Apex domains cannot have CNAME records.
Question and response
Question
dig tyrala.de. NS
Answer
tyrala.de. 5 NS dns.tyrala.de.
tyrala.de. 5 NS dns3.tyrala.de.
Authority
The response has no authority records.
Additional
dns.tyrala.de. 5 A 212.132.106.16
dns3.tyrala.de. 5 A 217.154.86.171
dns.tyrala.de. 5 AAAA 2a01:239:2c1:af00:0:0:0:1
dns3.tyrala.de. 5 AAAA 2a01:239:3a3:a700:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0