Wrong Finger ID registered with OnPointerUp()

Hi, I'm having a big problem with the Unity 5 touch controls. I made a test project, imported the CrossPlatformInput asset and just put the MobileSingleStickControl prefab in my scene. I then tested it with Unity Remote but I noticed something which bothers me a lot: if I drag the joystick with one finger, then put another finger anywhere else on the screen and then lift this finger, then the joystick will be reset to its original position. I tested the script and noticed that it believes the finger that was removed from the touchscreen is the same that was on the joystick. Does anyone know how to fix this? I've tried everything, including using Input.GetTouch() instead of CrossPlatformInput but I always have the same problem.