Apex domains cannot have CNAME records.
Question and response
Question
dig nixvau.lt. NS
Answer
nixvau.lt. 5 NS dns.vlt81.de.
nixvau.lt. 5 NS ns1.1984.is.
nixvau.lt. 5 NS ns0.1984.is.
nixvau.lt. 5 NS ns2.1984hosting.com.
Authority
The response has no authority records.
Additional
dns.vlt81.de. 5 A 176.9.242.147
ns0.1984.is. 5 A 45.76.37.222
ns1.1984.is. 5 A 194.58.192.36
dns.vlt81.de. 5 AAAA 2a01:4f8:2200:44a1:0:0:baad:c0de
ns0.1984.is. 5 AAAA 2001:19f0:5001:185a:5400:ff:fe50:56d5
ns1.1984.is. 5 AAAA 2a01:3f1:36:0:0:0:0:53
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0