I have found a pretty serious bug on the AMD drivers where if CCC is set to "Maximum Performance" on Switchable Graphics, it will force all XAML applications to run on the dGPU (AMD). Ultimately XAML fails to run on AMD and nothing ends up working. At that point Spartan/Edge is the least of your worries since the Start Menu / Apps / Login doesn't work. I hope it is not the same bug.