Apex domains cannot have CNAME records.
Question and response
Question
dig saowifi.net. NS
Answer
saowifi.net. 2 NS ns.saocomp.cz.
saowifi.net. 2 NS ns.paskov.cz.
Authority
The response has no authority records.
Additional
ns.paskov.cz. 1 A 161.97.166.226
ns.saocomp.cz. 1 A 31.222.0.3
ns.paskov.cz. 1 AAAA 2a02:c206:2150:2584:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0