[Samba] Can't join AD

[lists at zxt10d.de]

Hello list,

I can't find the mistake causing the problem ... maybe you do.
A Windows 2022 Server can't join the AD.

Debian Bookworm
Samba Version: 4.19.6-Debian
ip: 192.168.10.11

Windows Server 2022
ip: 192.168.10.15
subnet: 255.255.255.0
gateway: 192.168.10.1 -> FritzBox
1st DNS: 192.168.10.11
2nd DNS: 192.168.10.12 -> dc02

When entering the domain-name to the "member of domain"-field, and then 
using administrator with the (working!) password, I get a
"Networkpath not found"-message (its translated from german).

When doing a:
nslookup dc01.praxis.domain.tld
on the Windos-system it jumps to the gateway (its a FritzBox), and tries 
to resolve dc01.praxis.domain.tld on the internet.

/etc/network/interfaces:
auto lo
iface lo inet loopback
allow-hotplug ens18
#
iface ens18 inet6 auto
#
iface ens18 inet static
address 192.168.10.11
netmask 255.255.255.0
network 192.168.10.0
broadcast 192.168.10.255
gateway 192.168.10.1

/etc/resolv.conf:
search praxis.domain.tld
nameserver 192.168.10.11

/etc/hosts:
127.0.0.1       localhost
192.168.10.11   dc01.praxis.dr-ts.de    dc01

/etc/samba/smb.conf:
[global]
         dns forwarder = 192.168.10.11
         netbios name = DC01
         realm = PRAXIS.DR-TS.DE
         server role = active directory domain controller
         workgroup = PRAXIS
         idmap_ldb:use rfc2307 = yes

[sysvol]
         path = /var/lib/samba/sysvol
         read only = No

[netlogon]
         path = /var/lib/samba/sysvol/praxis.dr-ts.de/scripts
         read only = No

Thanks in advance!
Torsten