Apex domains cannot have CNAME records.
Question and response
Question
dig vdxhost.com. NS
Answer
vdxhost.com. 3 NS michelle.ns.cloudflare.com.
vdxhost.com. 3 NS nico.ns.cloudflare.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0