Same issue here! There doesn't seem to be any way in Intel's Command Center, Arc Control, NVIDIA Control Panel, Graphics settings or Device Manager. Windows just chooses the wrong GPU to assign to High Performance.
We don't want to disable the Intel Arc as I use mine for Stream capture while I'm gaming on the NVIDIA Card and I don't want to have to add every single application and change them manually to use the "Power Saving" GPU because by default Windows chooses high performance for games and that is the wrong GPU!
Fix this!!