vmi2542200.contaboserver.net has no CNAME records.
Question and response
Question
dig vmi2542200.contaboserver.net. NS
Answer
The response has no answer records.
Authority
contaboserver.net. 2494 SOA ns1.contabo.net. hostmaster.contabo.de. 1771723369 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0