Apex domains cannot have CNAME records.
Question and response
Question
dig app.jaggaer.com. NS
Answer
app.jaggaer.com. 4 NS ns-21.awsdns-02.com.
app.jaggaer.com. 4 NS ns-775.awsdns-32.net.
app.jaggaer.com. 4 NS ns-1442.awsdns-52.org.
app.jaggaer.com. 4 NS ns-1683.awsdns-18.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0