Apex domains cannot have CNAME records.
Question and response
Question
dig howtogetridofmucus.com. NS
Answer
howtogetridofmucus.com. 5 NS ns-473.awsdns-59.com.
howtogetridofmucus.com. 5 NS ns-432.awsdns-54.com.
howtogetridofmucus.com. 5 NS ns-316.awsdns-39.com.
howtogetridofmucus.com. 5 NS ns-1240.awsdns-27.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0