I had a similar problem with one of mine. It worked OK, but it was very hard to find the diagonals on one side. I took it apart, cleaned it all off, and reassembled and it is working better.
For some reason the diagonals are still not as good as the other P360 I have (which works perfectly). I suspect that there may be a slight misalignment of the optics on one of the sensor-led pairs, so I'm leaning towards dissassembling it again to check alignment. It was not the actuator - as I already replaced that with no effect.
Still overally I prefer the 360's to my old conventional joysticks - they are much quicker and more responsive.
Cheers!
Doc -