Apex domains cannot have CNAME records.
Question and response
Question
dig web.uc.dgc.se. NS
Answer
web.uc.dgc.se. 5 NS udns2.ultradns.net.
web.uc.dgc.se. 5 NS udns1.ultradns.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0