It's not just One-Drive.
If you hover over the UNSUPPORTED FILE SYSTEM message, mine says E:/SteamLibrary\SteamApps\downloading\1234567\Data\Localization\Voice.pak
My E: drive is a USB drive that I use for some of my barely used games. It's not where BG3 is installed and it's not the correct format.
So for some reason it wants to save the voice.pak there.
