nas.pflegedienst-johnson.com has no CNAME records.
Question and response
Question
dig nas.pflegedienst-johnson.com. NS
Answer
The response has no answer records.
Authority
pflegedienst-johnson.com. 3147 SOA ns.pflegedienst-johnson.com. mail.pflegedienst-johnson.com. 105 900 600 86400 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0