Apex domains cannot have CNAME records.
Question and response
Question
dig online-access.com. NS
Answer
online-access.com. 5 NS dns34.cloudns.net.
online-access.com. 5 NS dns31.cloudns.net.
online-access.com. 5 NS dns32.cloudns.net.
online-access.com. 5 NS dns33.cloudns.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0