schwoerer-test.managed-otrs.com has no CNAME records.
Question and response
Question
dig schwoerer-test.managed-otrs.com. NS
Answer
The response has no answer records.
Authority
managed-otrs.com. 876 SOA ns10.managed-otrs.com. dnsmaster.otrs.com. 964779163 3600 1800 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0