Apex domains cannot have CNAME records.
Question and response
Question
dig sarglasgow.com. NS
Answer
sarglasgow.com. 5 NS ns-1726.awsdns-23.co.uk.
sarglasgow.com. 5 NS ns-1427.awsdns-50.org.
sarglasgow.com. 5 NS ns-2014.awsdns-59.co.uk.
sarglasgow.com. 5 NS ns-1983.awsdns-55.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0