Apex domains cannot have CNAME records.
Question and response
Question
dig ipv4.ceb02.ds.network. NS
Answer
ipv4.ceb02.ds.network. 5 NS names1.ds.network.
ipv4.ceb02.ds.network. 5 NS names2.ds.network.
Authority
The response has no authority records.
Additional
names1.ds.network. 5 A 27.124.125.3
names2.ds.network. 5 A 27.124.125.4
names1.ds.network. 5 AAAA 2a00:fd80:aaaa:ffff:0:0:aaaa:1
names2.ds.network. 5 AAAA 2a00:fd80:aaaa:ffff:0:0:aaaa:2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0