Apex domains cannot have CNAME records.
Question and response
Question
dig stcable.net. NS
Answer
stcable.net. 4 NS bind-2.sattrakt.net.
stcable.net. 4 NS bind-1.sattrakt.net.
Authority
The response has no authority records.
Additional
bind-1.sattrakt.net. 4 A 81.24.247.40
bind-2.sattrakt.net. 4 A 81.24.247.58
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0