How to delete another user's Hello data

Question

I have a tablet (Surface Pro 4 256GB) that, on the login screen, is giving off a "Something went wrong, please enter your pin" error.

This started when I tried to delete the two .dat files in C:\Windows\System32\WinBioDatabase\, following this post.
I've looked at other guides on how to delete another user's Hello data in case if this guide was wrong, but everything I find on google is essentially identical.
I initially tried to delete the data because at log in, Hello was trying to do facial recognition and having a message about attempting it. The user who set this up no longer works here.

If I stop the Windows Biometric Service and disable the Windows Hello Face Software Device, I can delete both of them.
If I reboot, one of them returns.

If I set the Windows Biometric service to Manual, it still runs on startup and re-creates the file.

If I set the Windows Biometric Service to Disabled (preventing it from starting in the first place), then delete the remaining one, neither of them return.

If I re-enable the Biometric Service and the Hello Face Software Device, both of them return, and so does the error.

Also, if the Hello device is disabled, the error changes from "Something went wrong" to "Camera not available."
If the Hello device is enabled and the Biometric Service disabled, there is no error, just the animated icon for Hello.

I've also went to delete the user from HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList, but the user doesn't have an entry there anymore.

In between every step and seeing the result, I've rebooted.
I've repeated all of these steps at least 3 times to confirm it's not a one time error.

Also, if I enable the Biometric Service, no rebooting, I notice both files are immediately back, they don't wait for a reboot to return.

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Why do these files keep coming back, and how can I stop it? And is this even the source of my initial error?