Apex domains cannot have CNAME records.
Question and response
Question
dig hostatom.com. NS
Answer
hostatom.com. 1 NS thms1.hostatom.com.
hostatom.com. 1 NS thms2.hostatom.com.
Authority
The response has no authority records.
Additional
thms1.hostatom.com. 1 A 27.254.145.141
thms2.hostatom.com. 1 A 66.70.240.62
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0