Apex domains cannot have CNAME records.
Question and response
Question
dig uberns.org. NS
Answer
uberns.org. 5 NS c1.uberns.org.
uberns.org. 5 NS d1.uberns.org.
uberns.org. 5 NS a1.uberns.org.
uberns.org. 5 NS b1.uberns.org.
Authority
The response has no authority records.
Additional
a1.uberns.org. 5 A 216.59.59.3
b1.uberns.org. 5 A 216.59.57.1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0