srv1.hetzner.dotplex.net has no CNAME records.
Question and response
Question
dig srv1.hetzner.dotplex.net. NS
Answer
The response has no answer records.
Authority
dotplex.net. 3460 SOA ns.dotplex.net. support.dotplex.com. 2026022601 86400 10800 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0