Apex domains cannot have CNAME records.
Question and response
Question
dig planisys.io. NS
Answer
planisys.io. 5 NS dns3.planisys.tech.
planisys.io. 5 NS globaldns1.planisys.net.
planisys.io. 5 NS dns5.planisys.io.
planisys.io. 5 NS globaldns2.planisys.net.
Authority
The response has no authority records.
Additional
dns3.planisys.tech. 5 A 63.251.107.116
dns5.planisys.io. 5 A 143.42.183.85
dns5.planisys.io. 5 AAAA 2600:3c03:0:0:f03c:93ff:fe99:49bd
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0