Apex domains cannot have CNAME records.
Question and response
Question
dig ip-217-182-111.eu. NS
Answer
ip-217-182-111.eu. 5 NS dns17.ovh.net.
ip-217-182-111.eu. 5 NS ns17.ovh.net.
Authority
The response has no authority records.
Additional
ns17.ovh.net. 4 A 5.39.116.57
dns17.ovh.net. 4 A 5.135.112.105
ns17.ovh.net. 4 AAAA 2001:41d0:b00:f000:0:0:0:2
dns17.ovh.net. 4 AAAA 2001:41d0:d00:f600:0:0:0:2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0