Apex domains cannot have CNAME records.
Question and response
Question
dig planet-work.com. NS
Answer
planet-work.com. 5 NS ns3.planet-work.com.
planet-work.com. 5 NS ns2.planet-work.com.
planet-work.com. 5 NS ns1.planet-work.com.
Authority
The response has no authority records.
Additional
ns1.planet-work.com. 5 A 79.99.164.2
ns2.planet-work.com. 5 A 79.99.165.2
ns3.planet-work.com. 5 A 212.83.132.53
ns1.planet-work.com. 5 AAAA 2a01:648:0:0:0:0:0:2
ns2.planet-work.com. 5 AAAA 2a01:648:0:4:0:0:0:2
ns3.planet-work.com. 5 AAAA 2001:bc8:3061:103:0:0:0:53
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0