Infuriating bug: Android build occasionally dropping touch input.

In brief:

• I'm checking for touch input at the top of Update()

• I'm checking for touch input through NGUI's OnPress method

When running the app, every so often (perhaps 10% of the time) a direct touch to the phone screen will not be registered as a touch. This means that my bool flags are not set, and Input.touchCount is 0.

• If I leave my finger held down on the phone, at no point will a touch be registered until I release the touch and repress.

• If I drag my finger on a missed touch event, the touch input will flick on and off sporadically over the course of the drag phase.

I do not believe this is an issue of hidden UI elements consuming touch. I am tracking Input.touchCount which should register touch regardless of whether the input is being consumed by an NGUI element. I am also testing NGUI touch input separately.

Adb logging suggests that EventDispatch isn't recognising the touch when touch is missed. I'm running the app on a Galaxy J7. I have not experienced any dropped touch input in other apps. I'm running Unity 5.3.0f4.

At this point even just a suggestion would be great!