Apex domains cannot have CNAME records.
Question and response
Question
dig tuxis.net. NS
Answer
tuxis.net. 5 NS nssecauth2.tuxis.net.
tuxis.net. 5 NS nssecauth1.tuxis.net.
Authority
The response has no authority records.
Additional
nssecauth1.tuxis.net. 5 A 31.3.104.54
nssecauth2.tuxis.net. 5 A 185.119.31.20
nssecauth1.tuxis.net. 5 AAAA 2a03:7900:2:0:31:3:104:54
nssecauth2.tuxis.net. 5 AAAA 2a03:7900:501:0:185:119:31:20
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0