Apex domains cannot have CNAME records.
Question and response
Question
dig hostingdomainserver.com. NS
Answer
hostingdomainserver.com. 5 NS ns-1915.awsdns-47.co.uk.
hostingdomainserver.com. 5 NS ns-1523.awsdns-62.org.
hostingdomainserver.com. 5 NS ns-559.awsdns-05.net.
hostingdomainserver.com. 5 NS ns-1847.awsdns-38.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0