Apex domains cannot have CNAME records.
Question and response
Question
dig reliability-test-services.com. NS
Answer
reliability-test-services.com. 1 NS ns2.reliability-test-services.com.
reliability-test-services.com. 1 NS ns1.reliability-test-services.com.
Authority
The response has no authority records.
Additional
ns1.reliability-test-services.com. 1 A 149.56.130.74
ns2.reliability-test-services.com. 1 A 15.235.97.235
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0