Apex domains cannot have CNAME records.
Question and response
Question
dig changeworknow.co.uk. NS
Answer
changeworknow.co.uk. 5 NS veda.ns.cloudflare.com.
changeworknow.co.uk. 5 NS leonidas.ns.cloudflare.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0