I only tested with my xbox one controller so there was bound to be some issues. I plugged in my DS4 and there was also some sticking issue that I think I may have fixed, but the button mapping is off from the way xbox binds and only the stick works, not the d-pad, so it's a little funky to play with a DS4 right now.
I don't know if you mean a literal playstation 2 keyboard or if that's some terminology I'm unfamiliar with but I'm not sure what the problem could be other than the controller stuck forcing a direction.
Not sure if the sticking issue I was encountering is the same as the problems you were having but I uploaded a new version if you feel like giving it a shot. If not no worries. Sorry for the hassle either way!