I'm really sorry hamhead, but Switch Pro Controller is not a standard PC controller and thus it is untested & we don't officially support it.
Here's two things to try if you haven't already:
- Play Fossil Hunters through Steam, taking advantage of their controller API https://www.pcgamer.com/how-to-use-a-nintendo-switch-pro-controller-on-pc/
- Use the Switch Pro Controller with a device like the 8BitDo Wireless USB Adapter https://www.8bitdo.com/wireless-usb-adapter/, which essentially turns the Switch Pro Controller into an XBox Controller (XInput) which we designed the game to be played with.
For best results try an XInput controller like the Xbox 360 or Xbox One controller. Please let me know how it goes! Thanks for playing.