Apex domains cannot have CNAME records.
Question and response
Question
dig net.unitedlayer.com. NS
Answer
net.unitedlayer.com. 5 NS ns3.unitedlayer.com.
net.unitedlayer.com. 5 NS ns2.unitedlayer.com.
net.unitedlayer.com. 5 NS ns1.unitedlayer.com.
net.unitedlayer.com. 5 NS ns4.unitedlayer.com.
Authority
The response has no authority records.
Additional
ns3.unitedlayer.com. 5 A 209.237.230.130
ns4.unitedlayer.com. 5 A 207.7.150.77
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0