I had similar problems. The workaround was that both launchers, steam and larian shouldnt openwhen the game starts.
For this you have to first put "--skip-launcher" into the startup options of baldurs gate in the steam launcher. You find them when right clicking the game and then selecting "properties". (This prevents the Larian Launcher from opening)
Then you have to properly close steam, so that its not even open in the background. Afterwards you can start the game itself by starting the .exe. You should find it under "C:\Program Files (x86)\Steam\SteamApps\common\Baldurs Gate 3\bin". The exe for directx11 is called "bg3_dx11", the "bg3" one is for vulcan. (I am also starting the exe as an administrator, idk if this is needed tho)
Hope this helps. Good luck!
Last edited by Janob01; 25/12/23 09:21 PM. Reason: Better wording