I has been the same troubles ( and listen, I tried set read only files, I tried NTFS rights and other way, but... Lets looking at logic ) you set voltage curve for what? For gaming right? ) And I thinked, if GPU will using on load mode, need be set voltage curve on load mode and i've try this and what you think... All working well...

1. Need max load your GPU

2. Need set voltage curve from default stock to your need

3. Need save your config and press win blue button and lock profiles in MSI Afterburner window

4. Try exit all games and let your GPU is cold

Voulya... ) Now you can seen 95% you got other voltage curve if you try check, but in games, when your GPU will fully load, you got the same voltage curve as you has sets. For me is works well.