Apex domains cannot have CNAME records.
Question and response
Question
dig xpd.se. NS
Answer
xpd.se. 5 NS nx3.xpd.se.
xpd.se. 5 NS nx1.xpd.se.
xpd.se. 5 NS a.dns.tele2.net.
xpd.se. 5 NS b.dns.tele2.net.
Authority
The response has no authority records.
Additional
nx1.xpd.se. 5 A 194.58.192.50
nx3.xpd.se. 5 A 185.42.137.103
nx1.xpd.se. 5 AAAA 2a01:3f1:50:0:0:0:0:53
nx3.xpd.se. 5 AAAA 2a01:3f0:400:0:0:0:0:50
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0