Apex domains cannot have CNAME records.
Question and response
Question
dig groove.co. NS
Answer
groove.co. 5 NS ns-1806.awsdns-33.co.uk.
groove.co. 5 NS ns-1010.awsdns-62.net.
groove.co. 5 NS ns-362.awsdns-45.com.
groove.co. 5 NS ns-1527.awsdns-62.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0