Best guess would be a conflict in the house of cards -- having all three GPUs in the system with their associated drivers and software is not a recipe for stability. What happens if you disable the nVidia GPU?  
So recently I have purchased an external GPU for my laptop for gaming, software's, etc. Recently I have been having an issue where it will be using the external card and then randomly switching to the integrated GPU while I'm gaming. I've set the nvideo co trol panel to high performance, the amd app to high performance, the settings to high.  If anyone has a solution it would be amazing
Laptop switching to integrated graphics while using external graphics card