So, I've been trying to use an Xbox One controller on my PC to play this game, but while it recognizes it when I plug it in, it doesn't seem to register any button presses or directionals. I've double checked on my PC that Windows itself recognizes they're being pressed, so it must be an issue with the game.

EDIT: Using Windows 10 Pro, Titan Pascal, Intel Core7 6700K, if any of that matters.

I'm also having the exact same issue with a Nintndo Fight Pad Controller. It detects that I have it plugged in and when I go into the controls through settings, it shows a controller on screen when I hit any button. Furthermore the controls at the bottom screen show controller buttons. I also checked my controller in the devices and printer panel and ran a calibrate and tested that all the buttons are working as intended. Proving that my controller is perfectly healthy. 

This issue does not occur with dinput controllers such as the PS4/3 controller.