Apex domains cannot have CNAME records.
Question and response
Question
dig tvcabo.mz. NS
Answer
tvcabo.mz. 2 NS ns1.netcabo.co.mz.
tvcabo.mz. 2 NS ns2.netcabo.co.mz.
Authority
The response has no authority records.
Additional
ns1.netcabo.co.mz. 3 A 196.46.0.225
ns2.netcabo.co.mz. 3 A 196.46.0.226
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0