Pressure Plates activate even when not on the plate.
On the above screenshot, I am standing 1 block across, and yet the plate is activated. The same is true even if I stand on the sticky piston to the left, or on the hopper to the right.
The system on the screenshot broke for version 0.16.0, so I believe the bug arose during the update.
Breaking/replacing the plate or any of the components did not fix the bug.