Apex domains cannot have CNAME records.
Question and response
Question
dig thl.emergisssi.com. NS
Answer
thl.emergisssi.com. 5 NS dns3.emergisssi.com.
thl.emergisssi.com. 5 NS dns2.emergisssi.com.
thl.emergisssi.com. 5 NS dns1.emergisssi.com.
Authority
The response has no authority records.
Additional
dns1.emergisssi.com. 4 A 216.168.146.46
dns2.emergisssi.com. 4 A 216.168.146.47
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0