Apex domains cannot have CNAME records.
Question and response
Question
dig bcnencomu.cat. NS
Answer
bcnencomu.cat. 5 NS ns-88-c.gandi.net.
bcnencomu.cat. 5 NS ns-88-b.gandi.net.
bcnencomu.cat. 5 NS ns-14-a.gandi.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0