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