Apex domains cannot have CNAME records.
Question and response
Question
dig maxcluster.net. NS
Answer
maxcluster.net. 5 NS primary.maxnameserver.net.
maxcluster.net. 5 NS secondary.maxnameserver.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0