ns4.dnsbycomodo.net has no CNAME records.
Question and response
Question
dig ns4.dnsbycomodo.net. NS
Answer
The response has no answer records.
Authority
dnsbycomodo.net. 4236 SOA ns1.dnsbycomodo.net. admin.dnsbycomodo.com. 2019110746 14400 3600 1209600 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0