VCO-Server.vcosa.com has no CNAME records.
Question and response
Question
dig VCO-Server.vcosa.com. NS
Answer
The response has no answer records.
Authority
vcosa.com. 10800 SOA vcosa.com. root.vcosa.com. 2022101001 28800 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0