Apex domains cannot have CNAME records.
Question and response
Question
dig prosystemfx.net. NS
Answer
prosystemfx.net. 3 NS ns-1471.awsdns-55.org.
prosystemfx.net. 3 NS ns-1715.awsdns-22.co.uk.
prosystemfx.net. 3 NS ns-510.awsdns-63.com.
prosystemfx.net. 3 NS ns-797.awsdns-35.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0