eGPU Issue

For some reason, this game does not like eGPU’s. My laptop has an internal GT750m. So, I cannot run a game like this if I were to use it. I choose to use my 8GB RX 480 instead. Only problem is, the game has a white screen that comes up, then it automatically closes unless I have my laptop’s internal screen on. Sure, the RX 480 still controls that display when it’s enabled, but Forza doesn’t know that, and thinks it’s still running off the default GPU. This sort of an issue needs fixed. I have yet to have another game have this sort of an issue, and it shouldn’t be one in the first place.