Apex domains cannot have CNAME records.
Question and response
Question
dig supersistemas.com.mx. NS
Answer
supersistemas.com.mx. 5 NS ns1.supersistemas.com.mx.
supersistemas.com.mx. 5 NS ns2.supersistemas.com.mx.
Authority
The response has no authority records.
Additional
ns1.supersistemas.com.mx. 5 A 65.99.225.207
ns2.supersistemas.com.mx. 5 A 65.99.225.208
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0