Apex domains cannot have CNAME records.
Question and response
Question
dig as33711.net. NS
Answer
as33711.net. 5 NS nl.ns.saddle.network.
as33711.net. 5 NS ns.saddle.network.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0