Apex domains cannot have CNAME records.
Question and response
Question
dig global.pin.se. NS
Answer
global.pin.se. 5 NS dc03.global.pin.se.
global.pin.se. 5 NS dc01.global.pin.se.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0