Server 2012 windows update stuck forever

I have a problem with Windows Server 2012 (NON R2). Basically, svchost/wuauserv is stuck using 100% of 1 core (and 2GB RAM), indefinitely.

I tried pretty much everything I found online:

• Made sure there is enough diskspace (8GB now)
• Used Reset tools like ResetWUEng.cmd and Reset-WindowsUpdate.ps1
• Did a:
  • "dism /online /cleanup-image /restorehealth"
  • sfc /scannow
  • cd C:\Windows\System32\wbem\AutoRecover -> for /f %s in ('dir /b *.mof *.mfl') do mofcomp %s"
• Used WindowsUpdateDiagnostic.diagcab
• Tried WSUS offline (also hangs)
• Set windows update to never update
• Restarting VM, Restarting windows update service
• Left it overnight
• Manually installed latest monthly rollup (Februari 2019). This installed, but windows update still uses 25% (1 core) CPU indefinitely

I searched everywhere and I don't know what to do except for reinstall windows. At this point I just want to know what the problem is.

In the log file, lots of:

DtaStor WARNING: Attempted to add URL http://download.windowsupdate.com/d/msdownload/update/software/updt/2019/01/windows8-rt-kb4480094-x64_760d29d4007187bd160761d09c6b6600a5a84249.msu for file dg0p1ABxh70WB2HQnGtmAKWoQkk= when file has not been previously added to the datastore

Thanks