Apex domains cannot have CNAME records.
Question and response
Question
dig ecircle.de. NS
Answer
ecircle.de. 2 NS ns3.ecircle.com.
ecircle.de. 2 NS ns1.ecircle.de.
ecircle.de. 2 NS ns2.ecircle.de.
Authority
The response has no authority records.
Additional
ns1.ecircle.de. 2 A 195.140.184.21
ns2.ecircle.de. 2 A 176.9.224.227
ns3.ecircle.com. 4 A 91.192.40.21
ns2.ecircle.de. 2 AAAA 2a01:4f8:150:5017:0:0:0:227
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0