Apex domains cannot have CNAME records.
Question and response
Question
dig frankmodels.com. NS
Answer
frankmodels.com. 5 NS ns-1551.awsdns-01.co.uk.
frankmodels.com. 5 NS ns-1635.awsdns-12.co.uk.
frankmodels.com. 5 NS ns-1707.awsdns-21.co.uk.
frankmodels.com. 5 NS ns-505.awsdns-63.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0