Apex domains cannot have CNAME records.
Question and response
Question
dig propersupport.com. NS
Answer
propersupport.com. 4 NS dns2.supremecenter.com.
propersupport.com. 4 NS dns1.supremecenter.com.
Authority
The response has no authority records.
Additional
dns1.supremecenter.com. 4 A 162.210.102.140
dns2.supremecenter.com. 4 A 198.23.56.4
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0