ele
I dont know much about this stuff, but this may be useful until you get a better answer from Barbie or someone else.
I know Nvidia has a setting within games called DLSS. I believe having it on is supposed to make your game run 4k? But if your monitor is 1080p or something you might as well turn it off. I know in my past this has saved a ton of resources.
Also are you seeing GPU usage through an overlay or something? Only reason why I ask, but im sure you've done this is i just want to suggest pressing CTRL + SHIFT + TAB which opens your task manager. Click see more and you can scroll to the right and see a breakdown of all apps using GPU usage and how much each app is using your GPU usage. Who knows, maybe somehow you enabled some sort of option in the update that enabled some sort of heavy resource you may be able to spot in task manager.
Hope this helps, if not, sometime tonight Barbie should respond helpfully.