Apex domains cannot have CNAME records.
Question and response
Question
dig as58436.net. NS
Answer
as58436.net. 5 NS pns1.cloud.sg.
as58436.net. 5 NS pns3.cloud.sg.
as58436.net. 5 NS ns10.dnsmadeeasy.com.
as58436.net. 5 NS pns2.cloud.sg.
as58436.net. 5 NS pns4.cloud.sg.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0