Unable to Switch to Keyboard-Only Controls (Locked to Keyboard + Mouse)

Hey mate, I fixed it using an external software called HidHide. Not sure if I'm allowed link it here so I won't, but basically it hides all of your HIDs from a specific .exe file (in this case FC26). HIDs are mostly keyboards, controllers etc. but even simple USBs can be recognized as such, and for some reason FC26 takes one of them and runs with it, while also cutting your option to change controller off.