Ok here is a strange one. This is happening on both virtual and physical DCs. Demoting to member server eliminates the problem. DCDiag shows everything is good.
After reboot, the DCs in our child domain won't always allow you to log in to the console(Master domain doesn't have any users)
If the network is not present, you can log in using cached creds.
It started a long time ago before I started working here, I thought I had fixed it with patching, but it impacts 2012r2 and 2016 (our domain is at 2008r2 currently, I just retired our old 2008r2 DC)
It was working fine until I had to force remove the last 2008r2 server from the DC pool, well at least it appeared it was.
Symptoms: Once rebooted ram spikes at max, vm reboots a bunch, and eventually stabilizes. ram still at 100%
If I reboot with network disconnected, everything starts up fine.
I've run dcdiag until I'm blue in the face looking for anything,