Apex domains cannot have CNAME records.
Question and response
Question
dig spacys.de. NS
Answer
spacys.de. 5 NS ns2.spacys.de.
spacys.de. 5 NS ns1.spacys.de.
Authority
The response has no authority records.
Additional
ns1.spacys.de. 5 A 178.63.9.212
ns2.spacys.de. 5 A 178.63.9.243
ns1.spacys.de. 5 AAAA 2a01:4f8:110:4443:0:0:0:8
ns2.spacys.de. 5 AAAA 2a01:4f8:110:4443:0:0:0:9
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0