Apex domains cannot have CNAME records.
Question and response
Question
dig teamleader.be. NS
Answer
teamleader.be. 5 NS ns-190.awsdns-23.com.
teamleader.be. 5 NS ns-831.awsdns-39.net.
teamleader.be. 5 NS ns-1523.awsdns-62.org.
teamleader.be. 5 NS ns-1602.awsdns-08.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0