Apex domains cannot have CNAME records.
Question and response
Question
dig xlhost.com. NS
Answer
xlhost.com. 5 NS dns4.ee.net.
xlhost.com. 5 NS dns2.ee.net.
xlhost.com. 5 NS dns3.ee.net.
Authority
The response has no authority records.
Additional
dns2.ee.net. 1 A 206.222.1.2
dns3.ee.net. 1 A 206.222.1.3
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0