static.221.50.161.5.clients.your-server.de has no CNAME records.
Question and response
Question
dig static.221.50.161.5.clients.your-server.de. NS
Answer
The response has no answer records.
Authority
161.5.clients.your-server.de. 1681 SOA ns1.your-server.de. postmaster.your-server.de. 2019092855 86400 1800 3600000 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0