Apex domains cannot have CNAME records.
Question and response
Question
dig efiservers.com. NS
Answer
efiservers.com. 5 NS ns2.efiservers.com.
efiservers.com. 5 NS ns1.efiservers.com.
efiservers.com. 5 NS ns4.efiservers.com.
efiservers.com. 5 NS ns3.efiservers.com.
Authority
The response has no authority records.
Additional
ns1.efiservers.com. 5 A 198.23.54.154
ns2.efiservers.com. 5 A 198.23.55.153
ns3.efiservers.com. 5 A 94.136.171.52
ns4.efiservers.com. 5 A 185.196.102.2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0