Apex domains cannot have CNAME records.
Question and response
Question
dig brightspace.com. NS
Answer
brightspace.com. 2 NS ns-108.awsdns-13.com.
brightspace.com. 2 NS ns-905.awsdns-49.net.
brightspace.com. 2 NS ns-1133.awsdns-13.org.
brightspace.com. 2 NS ns-1559.awsdns-02.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0