I had an issue in my lab where the PDC emulator changed his password while the IPv6 communication was not properly up and running, and so 2 different password were register on my 2 DCs, this remember that IPv6 is the preferred network in Windows and been like that since Vista.
Nothing new in the this article, but just some precision, as the documentation can be confusing sometimes and we tend to forget things.
The architecture is the following:
DC1 : Server 2012R2
DC2 : Server 2016 (All FMSO hosted) – The culprit
First thing to check is the DNS and point the network card of DC2 to the working DC, as DC2 DNS server might not be working properly, in my case DC2 didn’t had IPv6 records while DC1 had them and since the DNS zone is replicated via AD, we clearly see an issue here.