Turns out I didn't fully realize or understand the hard limit of 4 XInput compatible controllers in Windows boxes. I thought if you plugged them in it wouldn't be a limit, but no way. I also wished I had borrowed enough Xbox & PS4 controllers when testing it.
After some invaluable feedback from a player I took out XInput and utilize DirectInput now. So, now I have tested with the lot of them and the fix is up now to download: version 1.8.1.
Please update and have fun!
