Apex domains cannot have CNAME records.
Question and response
Question
dig fsdata.se. NS
Answer
fsdata.se. 5 NS ns.aname.net.
fsdata.se. 5 NS ns3.aname.se.
fsdata.se. 5 NS ns2.aname.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0