Apex domains cannot have CNAME records.
Question and response
Question
dig tmes-sg.trendmicro.com. NS
Answer
tmes-sg.trendmicro.com. 5 NS ns-268.awsdns-33.com.
tmes-sg.trendmicro.com. 5 NS ns-1622.awsdns-10.co.uk.
tmes-sg.trendmicro.com. 5 NS ns-1420.awsdns-49.org.
tmes-sg.trendmicro.com. 5 NS ns-997.awsdns-60.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0