bluebird.net.hostasaurus.com has no CNAME records.
Question and response
Question
dig bluebird.net.hostasaurus.com. NS
Answer
The response has no answer records.
Authority
hostasaurus.com. 7923 SOA ns3.hostasaurus.com. hostmaster.hostasaurus.com. 1769190313 16384 2048 1048576 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0