Apex domains cannot have CNAME records.
Question and response
Question
dig netuse.de. NS
Answer
netuse.de. 5 NS a11-67.akam.net.
netuse.de. 5 NS ns21.netuse.de.
netuse.de. 5 NS a6-66.akam.net.
netuse.de. 5 NS a16-65.akam.net.
netuse.de. 5 NS a7-67.akam.net.
netuse.de. 5 NS a1-130.akam.net.
netuse.de. 5 NS a14-64.akam.net.
Authority
The response has no authority records.
Additional
ns21.netuse.de. 5 A 52.137.9.10
a11-67.akam.net. 5 A 84.53.139.67
a11-67.akam.net. 5 AAAA 2600:1480:1:0:0:0:0:43
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0