Apex domains cannot have CNAME records.
Question and response
Question
dig acme-solution.com. NS
Answer
acme-solution.com. 5 NS ns-1869.awsdns-41.co.uk.
acme-solution.com. 5 NS ns-1413.awsdns-48.org.
acme-solution.com. 5 NS ns-91.awsdns-11.com.
acme-solution.com. 5 NS ns-1617.awsdns-10.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0