Apex domains cannot have CNAME records.
Question and response
Question
dig spectro.mx. NS
Answer
spectro.mx. 5 NS ns5.changeip.com.
spectro.mx. 5 NS ns6.changeip.com.
spectro.mx. 5 NS ns3.changeip.com.
spectro.mx. 5 NS ns1.changeip.com.
spectro.mx. 5 NS ns4.changeip.com.
spectro.mx. 5 NS ns2.changeip.com.
Authority
The response has no authority records.
Additional
ns1.changeip.com. 5 A 66.175.223.58
ns2.changeip.com. 5 A 69.164.221.190
ns3.changeip.com. 5 A 172.105.65.55
ns4.changeip.com. 5 A 172.105.55.163
ns5.changeip.com. 5 A 172.105.169.72
ns6.changeip.com. 5 A 192.46.230.71
ns1.changeip.com. 5 AAAA 2600:3c01:0:0:f03c:94ff:fe7c:462b
ns2.changeip.com. 5 AAAA 2600:3c03:0:0:f03c:94ff:fe63:61cf
ns3.changeip.com. 5 AAAA 2a01:7e01:0:0:f03c:94ff:feaf:2efb
ns4.changeip.com. 5 AAAA 2400:8904:0:0:f03c:94ff:feaf:8449
ns5.changeip.com. 5 AAAA 2400:8907:0:0:f03c:94ff:fe21:b6ac
ns6.changeip.com. 5 AAAA 2400:8901:0:0:f03c:94ff:fe6f:8ef
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0