ns02.idcfcloud.com has no CNAME records.
Question and response
Question
dig ns02.idcfcloud.com. NS
Answer
The response has no answer records.
Authority
idcfcloud.com. 490 SOA ns01.idc.jp. dns-support.idc.jp. 2019060668 10800 1800 3600000 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0