Apex domains cannot have CNAME records.
Question and response
Question
dig ams.resource.cloud. NS
Answer
ams.resource.cloud. 5 NS ns2.ams.teamblue.cloud.
ams.resource.cloud. 5 NS ns1.ams.teamblue.cloud.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0