Apex domains cannot have CNAME records.
Question and response
Question
dig aztecaservicios.mx. NS
Answer
aztecaservicios.mx. 4 NS ns2.f5clouddns.com.
aztecaservicios.mx. 4 NS ns1.f5clouddns.com.
aztecaservicios.mx. 4 NS ns4.aztecaservicios.mx.
aztecaservicios.mx. 4 NS ns22.aztecaservicios.mx.
aztecaservicios.mx. 4 NS ns23.aztecaservicios.mx.
aztecaservicios.mx. 4 NS ns3.aztecaservicios.mx.
Authority
The response has no authority records.
Additional
ns1.f5clouddns.com. 4 A 107.162.234.197
ns2.f5clouddns.com. 4 A 107.162.176.221
ns3.aztecaservicios.mx. 4 A 200.38.113.11
ns4.aztecaservicios.mx. 4 A 200.38.112.4
ns1.f5clouddns.com. 4 AAAA 2604:e180:1071:0:0:0:3:1
ns2.f5clouddns.com. 4 AAAA 2604:e180:1071:0:0:ffff:6ba2:b0dd
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0