Apex domains cannot have CNAME records.
Question and response
Question
dig bss.info. NS
Answer
bss.info. 5 NS docks10.rzone.de.
bss.info. 5 NS shades18.rzone.de.
Authority
The response has no authority records.
Additional
docks10.rzone.de. 2 A 217.160.80.137
shades18.rzone.de. 2 A 185.132.34.145
docks10.rzone.de. 2 AAAA 2001:8d8:fe:53:5747:2a74:d:10
shades18.rzone.de. 2 AAAA 2607:f1c0:fe:53:185:132:34:145
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0