Steps to reproduce:

1) Download attached project 'PointerBug.zip' and open in Unity.
2) Open scene 'Test'.
3) Connect Android device with Unity remote app running.
4) Click down on the ‘Test Button’ using the mouse.
5) Touch down or tap as much as you want on the ‘Test Button’ in the Unity Remote app.
Note: Check the Console tab and you will notice everything works as it should be.
6) Release the held mouse click. OnPointerUp does not get called. If you move the mouse cursor you’ll see logs suggesting that the mouse is dragging even though the mouse click was released.

Expected result: OnPointerUp should be called just after mouse button is released.

Actual result: OnPointerUp is not being called.

Reproduced with : 5.3.6p1, 5.4.0f2, 5.5.0a4

DUT:
Samsung Galaxy S6 edge