[Samba] Win10 cant connect to DomainController

[basti]

Hello,
I have a Win10 Client connected via openVPN to the company LAN.
openVPN seem to work fine. I get Routes, the AD DNS server, can ping
domain controller file Server etc.

Authendicaten on Fileserver fail (cant connect to domaincontroller)
gpupdate fail with the same error.

Firewall haas open all port list here:
https://wiki.samba.org/index.php/Samba_AD_DC_Port_Usage

I have try to debug with tcpdump but cant see any traffic that is not
answerd.

How can i fix?
Best regards