Apex domains cannot have CNAME records.
Question and response
Question
dig eb-web-service.com. NS
Answer
eb-web-service.com. 5 NS ns-5.awsdns-00.com.
eb-web-service.com. 5 NS ns-394.awsdns-49.com.
eb-web-service.com. 5 NS ns-705.awsdns-24.net.
eb-web-service.com. 5 NS ns-1914.awsdns-47.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0