ussnorway: yes something is messed up... your shader should not be rebuilding each boot without new patches which means its most likely a software [not hardware] problem
check:
what location is the game installed to ie, c/ program file/ bg3 or d Gog/ bg3?
is one drive installed [are any of the bg3 save files in it]?
look at your anti-virus software
also what Windows [7,10 or 11]? ... the difference between dx and vulcan is one uses gpu and the other cpu, you didn't tell us your Gpu so i would assume its not too great and therefore vulcan is the better option for you
It rebuilds the shader cache ever launch, it says this could take a while and it does lol. It hangs around 67% then hangs around 97% to 100%
The game location is C:\GOG Games\Baldurs Gate 3. Which is located in local disk C: I am running window 10 pro, which is update, on updates.
I have a metered internet connection, so I uninstalled One drive. I am using Malware bytes antivirus. Since you mentioned antivirus, I checked it, I have no threats detected, and I added Baldurs Gate 3 to the Allowed list. I still get the Shader cache rebuild every launch.
I tried DX11 launch a few times. It doesn't say generating shader cache, but takes just as long to load and hangs at the same spots, 67% and 97% to 100%.
My GPU is A Gigabyte 4070Ti I have the latest driver, the exact model is
https://www.gigabyte.com/Graphics-Card/GV-N407TGAMING-OCV2-12GD#kf I wished I had waited a little longer and got the super.
I am using Vulcan because it is supposedly better for AMD and I actually think the game looks better in Vulcan, than DX11