Apex domains cannot have CNAME records.
Question and response
Question
dig dynamic.amis.net. NS
Answer
dynamic.amis.net. 5 NS ns3.amis.net.
dynamic.amis.net. 5 NS ns1.amis.net.
dynamic.amis.net. 5 NS ns2.amis.net.
Authority
The response has no authority records.
Additional
ns1.amis.net. 5 A 212.18.32.5
ns2.amis.net. 5 A 80.95.234.33
ns3.amis.net. 5 A 212.18.32.142
ns1.amis.net. 5 AAAA 2001:15c0:ffff:f:0:0:0:5
ns2.amis.net. 5 AAAA 2a00:1a20:40:2:0:0:0:12
ns3.amis.net. 5 AAAA 2001:15c0:ffff:12:0:0:0:140
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0