Apex domains cannot have CNAME records.
Question and response
Question
dig sge.net. NS
Answer
sge.net. 5 NS dns4.sge.net.
sge.net. 5 NS dns3.sge.net.
sge.net. 5 NS dns1.sge.net.
sge.net. 5 NS dns2.sge.net.
Authority
The response has no authority records.
Additional
dns1.sge.net. 5 A 152.91.11.1
dns2.sge.net. 5 A 152.91.14.25
dns3.sge.net. 5 A 203.2.208.3
dns4.sge.net. 5 A 203.2.208.4
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0