static.55.154.34.188.clients.your-server.de has no CNAME records.
Question and response
Question
dig static.55.154.34.188.clients.your-server.de. NS
Answer
The response has no answer records.
Authority
34.188.clients.your-server.de. 10538 SOA ns1.your-server.de. postmaster.your-server.de. 2019093127 86400 1800 3600000 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0