Apex domains cannot have CNAME records.
Question and response
Question
dig granatua.net. NS
Answer
granatua.net. 4 NS nsd3.srv53.org.
granatua.net. 4 NS nsb1.srv53.net.
granatua.net. 4 NS nsd3.srv53.com.
granatua.net. 4 NS nsa1.srv53.com.
granatua.net. 4 NS nsc3.srv53.com.
granatua.net. 4 NS nsb4.srv53.org.
granatua.net. 4 NS nsa1.srv53.net.
granatua.net. 4 NS nsa3.srv53.org.
granatua.net. 4 NS nsc1.srv53.net.
granatua.net. 4 NS nsc3.srv53.org.
granatua.net. 4 NS nsb2.srv53.com.
granatua.net. 4 NS nsd3.srv53.net.
Authority
The response has no authority records.
Additional
nsa1.srv53.com. 4 A 178.32.247.7
nsd3.srv53.org. 4 A 89.184.64.96
nsa1.srv53.com. 4 AAAA 2001:41d0:203:dee4:178:32:247:7
nsd3.srv53.org. 4 AAAA 2a02:2278:70eb:298:89:184:64:96
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0