Apex domains cannot have CNAME records.
Question and response
Question
dig ns2.msdata.at. NS
Answer
ns2.msdata.at. 3 NS ns2.msdata.at.
ns2.msdata.at. 3 NS dns2.msdata.at.
ns2.msdata.at. 3 NS ns1.msdata.at.
ns2.msdata.at. 3 NS ns3.msdata.at.
Authority
The response has no authority records.
Additional
ns1.msdata.at. 3 A 5.132.162.120
ns2.msdata.at. 3 A 116.203.116.58
ns3.msdata.at. 3 A 65.109.169.120
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0