Apex domains cannot have CNAME records.
Question and response
Question
dig dnsexit.com. NS
Answer
dnsexit.com. 5 NS pm1.dnsexit.com.
dnsexit.com. 5 NS ns1.dnsexit.com.
dnsexit.com. 5 NS ns3.dnsexit.com.
dnsexit.com. 5 NS ns2.dnsexit.com.
dnsexit.com. 5 NS ns4.dnsexit.com.
dnsexit.com. 5 NS pm2.dnsexit.com.
Authority
The response has no authority records.
Additional
ns1.dnsexit.com. 5 A 31.14.40.88
ns2.dnsexit.com. 5 A 173.208.164.34
ns3.dnsexit.com. 5 A 204.12.192.106
ns4.dnsexit.com. 5 A 107.150.58.186
pm1.dnsexit.com. 5 A 162.244.80.162
pm2.dnsexit.com. 5 A 64.182.215.11
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0