Apex domains cannot have CNAME records.
Question and response
Question
dig pn.cegid.cloud. NS
Answer
pn.cegid.cloud. 5 NS a5-65.akam.net.
pn.cegid.cloud. 5 NS a20-64.akam.net.
pn.cegid.cloud. 5 NS a11-65.akam.net.
pn.cegid.cloud. 5 NS a14-66.akam.net.
pn.cegid.cloud. 5 NS a16-67.akam.net.
pn.cegid.cloud. 5 NS a1-170.akam.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0