[Samba] Internal DNS entries not created on Domain join of Windows computer, but with Linux it works!?

[Jakob Curdes]

Hi all,

we are trying to setup a samba4 domain. It is not our first production 
setup, so I am really wondering what I am doing wrong here.
We use Ubuntu 20 and the Van Belle repository (which probably is not 
important here). We provisioned the domain with the internal DNS backend.

We can provision the domain, do all tests, we can join a linux system to 
that domain and it will get listed in the DNS zone automatically.

However when we join a Windows system, the join works, the computer 
shows up in the domain with its machine account as expected, but the DNS 
entry is not created.
We made sure the only DNS server entered in the Windows system is the 
domain controller. We see no suspicious messages on the DC or the system 
that joined.

If we later do a ipconfig /registerdns, the Windows computer shows up in 
the AD DNS zone immediately.

What could be wrong here? We are already on the third round of re-doing 
everything from the beginning, so I would be very glad if anybody has an 
idea where to start troubleshooting.

Thank you for helping,
Jakob