Apex domains cannot have CNAME records.
Question and response
Question
dig thrifty.net. NS
Answer
thrifty.net. 4 NS ns4.lsn.net.
thrifty.net. 4 NS ns3.lsn.net.
Authority
The response has no authority records.
Additional
ns3.lsn.net. 4 A 66.90.130.24
ns4.lsn.net. 4 A 66.90.132.163
ns3.lsn.net. 4 AAAA 2607:e400:1002:0:66:90:130:24
ns4.lsn.net. 4 AAAA 2607:e400:6002:0:66:90:132:163
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0