Hello ausloki. Did you ever get this resolved? I ran into the same issue about 6 months ago and never figured it out. Didn’t matter if I used Server 2012 or 2016. I never could claim the server. Gave up and installed Windows 10 on the same hardware with the same ip address and everything worked. I find myself once again wanting to use a Server Operating System on newer hardware (so I can team the NICs) and same issue… installs fine but unable to claim the server.
I’m almost thinking it’s a permissions problem somewhere because I did get a message about “save unsuccessful” or something like that…
Anyway, if you figured this out, I would appreciate hearing from you. Thanks!