Apex domains cannot have CNAME records.
Question and response
Question
dig aphongxing.com. NS
Answer
aphongxing.com. 5 NS ns2.diamfair.com.
aphongxing.com. 5 NS ns1.diamfair.com.
Authority
The response has no authority records.
Additional
ns1.diamfair.com. 5 A 57.131.4.202
ns2.diamfair.com. 5 A 57.131.4.202
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0