Hi!
 
I noticed that when I run OC scanner in the latest version of Precision X1 (I have an EVGA 2080 XC), the changed VF curve is persistent after rebooting the system, even though I did not enable "Start with OS" and I also did not enable "Apply previous settings on load". I am not even running Precision X1 manually. I just started GPU-Z and saw that the OC clocks are still applied after reboot. Opening X1 directly shows the altered VF curve.
 
I even completely uninstalled X1, deleted all its folders and rebooted several times, and the OC is still applied. How can this be? Does it store the VF curve somewhere in registry which then gets loaded by the Nvidia driver itself?
If I use MSI Afterburner to set everything back to default, next time I reboot I again have the modified VF curve from Precision X1. Only workaround is to reset it to default using X1 and then uninstall X1. But again - how? How can this be without any X1 executable remaining on the system?

It is incorporated within the NVIDIA driver, saves to the driver, and is automatically applied after reboot via the driver without needing Precision or Afterburner re-applying it. This was announced by NVIDIA a year ago.

I noticed this when I updated to the latest version, after completely removing the previous version. Under the clock entry it still had "curve" and the OC was still the same.

Since I don't think I can post links here is some info I found
 

• OC Scanner is now integrated into Nvidia's drivers, instead of being integrated into the overclocking utility. This allows Nvidia to update OC Scanner on the fly without needing to consult programmers for each overclocking utility and get them to update their software. Third-party software will communicate with OC Scanner via the NVAPI.
• MSI Afterburner will support both versions of OC Scanner, depending on what graphics drivers you are using. you'll need Nvidia driver 456.xx or newer to use the new OC Scanner implementation.
• OC Scanner now supports automatic overclocking for both GPU and graphics memory.
• OC Scanner will save and apply its overclocks on a driver level and automatically apply them on reboot. So leaving your overclocking utility running in the background is no longer necessary.
• Manual adjustment of the voltage/frequency curve is no longer available. (i.e. this applies to OC Scanner overclocks only, you should have manual control of the voltage/frequency curve still.)

 
I would guess that this only applies to the voltage curve created by the OC Scanner.  Manually edited curves are probably loaded through your OC software (Afterburner, Precision).
 
If you have GeForce Experience installed you can reset the OC through the performance section of the overlay as well as change some basic things like power limit, fan speeds, and run the OC Scanner from there.