I ran into the issues above none of the fixes worked, however i did find an interesting work around, navigate to where ever your game is installed IE X:\SteamLibrary\steamapps\common\Baldurs Gate 3\bin change the compatibility as above to admin for all users on both EXE files "BG3" and "bg3_dx11" then run steam and the launcher
instead of using the play on the launcher tab over to the windows browser where the EXE files named above are hold Shift and Select both exe's simultaneously right click and hit open, this will try and launch them both at the same time, and prompt the ( allow run on this system (admin ) both games should flash and try to run, at this point usually but not always the DX 11 version will eventually crash, but the Vulcan version will now run normally.
Sometimes the other way around (Vulcan will crash dx 11 will succeed). If you tab between them you will see which one launched successfully then you can force end the one that has crashed or will eventually crash from the task manager and play away, this is the only reliable way to open the game that has worked for my windows 7 machine. best of luck!
