Non-existent names are resolved...

I have the problem that non-existent names always resolve to the same IP:

Ping wird ausgeführt für fdsafsd.xfsdf.zz [72.52.178.23] mit 32 Bytes Daten:
Ping wird ausgeführt für a123.notexist.ing [72.52.178.23] mit 32 Bytes Daten:

Antwort von 72.52.178.23: Bytes=32 Zeit=123ms TTL=49

Name: lb01.parklogic.com
Address:  72.52.178.23

The problem occurs with NextDNS (1.39.4) on a Synlogy NAS, with the following nextdns.conf

max-inflight-requests 256
auto-activate false
cache-size 20MB
max-ttl 5s
mdns all
timeout 5s
discovery-dns 192.168.178.1
detect-captive-portals false
hardened-privacy false
bogus-priv true
use-hosts true
setup-router true
log-queries false
cache-max-age 0s
report-client-info true
listen localhost:53
control /var/run/nextdns.sock
config fe6ae5
forwarder fritz.box.=192.168.178.1

How can this problem be solved?