Apex domains cannot have CNAME records.
Question and response
Question
dig nl.ext.origin-asp.com. NS
Answer
nl.ext.origin-asp.com. 5 NS ns2.atos.fr.
nl.ext.origin-asp.com. 5 NS ns2.atos-services.net.
nl.ext.origin-asp.com. 5 NS ns1.atos.fr.
nl.ext.origin-asp.com. 5 NS ns1.atos-services.net.
Authority
The response has no authority records.
Additional
ns1.atos.fr. 5 A 80.78.8.25
ns1.atos-services.net. 5 A 212.159.192.25
ns2.atos.fr. 5 A 80.78.8.60
ns2.atos-services.net. 5 A 212.159.225.215
ns1.atos-services.net. 5 AAAA 2a01:8180:3001:53:0:0:0:25
ns2.atos-services.net. 5 AAAA 2a01:8180:3002:53:0:0:0:215
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0