Hello.
I have a problem with 4.6 UI buttons on an Android 4.4.4 device (KitKat) requiring multiple presses to fire. The buttons are on an Image as content of a Scroll Rect. I have tried disabling the rect, mask and any images or panels in the area to no effect. The buttons work fine on an older device running Android 4.4.2 (JellyBean).
Any help much appreciated.
Regards.
The problem appears to be due to the drag threshold of the scroll rect as discussed here.
http://forum.unity3d.com/threads/buttons-within-scroll-rect-are-difficult-to-press-on-mobile.265682/
I was able to achieve slightly improved results by dropping the Scroll Rect Inertia deceleration rate to 0.001 and upping the Scroll Sensitivity value to 100.