Apex domains cannot have CNAME records.
Question and response
Question
dig 32.119.203.194.in-addr.arpa. NS
Answer
32.119.203.194.in-addr.arpa. 5 NS ns.emea.verizonbusiness.com.
32.119.203.194.in-addr.arpa. 5 NS auth200.ns.uu.net.
32.119.203.194.in-addr.arpa. 5 NS auth210.ns.uu.net.
Authority
The response has no authority records.
Additional
auth200.ns.uu.net. 5 A 195.129.12.82
auth210.ns.uu.net. 5 A 195.129.12.74
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0