Every time I login to the server it logs me as a temporary user

Did you try different accounts? If its with just one account, the profile seems to be corrupted.

tried local accounts (administrators), tried domain accounts (different administrators), delete profiles in the system / advanced, deleted registry entries for the profiles, no help

Did you try SAFE Mode?

I did not try safe mode, it is a virtual machine thought...

Please try safe mode and update us.

just tried, same thing...

Also tried non admin users, every time I get logged in as a temporary user

Try SFC and DISM. That fixes system files but I am not sure about Profiles.  Open cmd.exe with Run as Administrator and run:

1. SFC /SCANNOW    Allow it to complete and then run:
2. dism.exe   /online  /cleanup-image   /restorehealth
3. Windows Update to get all updates.

Now restart the server and test.   Let's hope this fixes the issue.

Already tried sfc, and updates. Did not try dism yet...

You may need to try a Repair Install if the repairs above do not work

is that an "online" repair?

You would need the Server ISO to get started and the Server needs Internet. You would have to restart after

Usually it is due to a corrupt profile or a corrupt, incomplete or missing default profile (see c:\Users\Default ) if you logged into it the first time.

Re-creating the profile differs between OS', so check this out https://neosmart.net/wiki/corrupt-user-profile/
So for Windows 2016, try the Windows 10 procedure.

did all that, and still no help...

I'll check the link on neosmart.net

Also look at how the Repair Install works.

Is this an RDS setup? Could be UPD settings or permissions where the profiles are stored. Redirected profiles as a gpo?

It is the RDS setup. I could check UPD settings and gpo...

RDS, yes probably something in there. Single gateway multiple servers? I always liked upd to a fileserver with redirected folders for docs and things to keep the upd small.

HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList and delete your old profile key that has a ending in s-1-5-21-*.................................bak.

Then you should be able to log on without an issue.

I deleted all of the profiles that I could delete, and I was unable to delete a "default" profile, and also deleted all of them in the registry ending with .bak.

The server is in the AD domain, but even if I login with the local user, admin or not, still end up with the temporary profile.

I could try to remove RDS feature just to see if there would be any change....

Farther back, I suggested a Server Repair Install. Did you try that?  Can you try it if you have not yet tried it?

because this a second RDS server, running wizard from the domain controller after I added the server to RD session host and collection, was meant to add RDS feature remotely from the server manager, but something went wrong there.

I tried dism image repair options. Did you mean something else?

Operating System Repair Install from the Server ISO.   If you run Setup from the ISO, it should launch a Repair of the Server machine.

ok,I'll try that now...

When deleting, you also gave to delete the objects from the profileguid

Usually, a temp profile with the .bak is fixed while the user is logged on, and renaming the user profile (temp reference) in profilelist to .crap while the .bak suffix is deleted, the user then needs to logout, login to reset to the correct profile.

operating system repair did not the fix the temporary profile issue

I'll have to reinstall windows 2016 on the same vm. Maybe it was a feature update that broke it...

I ended up reinstalling virtual machine, but I'll award points for help in troubleshooting

Thanks for the update