Better Repro:
- Open case_775756-TestDrag.7z project and its main scene
- Both sprites have a OnPointerClick event handler that logs the clicked object name.
- Both have a BoxCollider2D, both cameras have a PhysicsRaycaster2D
- when Cam_SmallFarClip is enabled, the bottom right sprite won't respond to clicks
- when Cam_BigFarClip is enabled, it works

This is apparently a bad interaction between the physics raycaster(and/or the event systems) and the perspective cam far clip plane.

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Reproduction steps:
1) Open project attached in the edit and proceed to "Main" scene.
2) Go into playmode.
3) Click and hold LMB - try dragging different areas of the screen(closer to the sides - as shown in GIF below).
4) Click on main camera and change Perspective camera Clipping Planes Far value to a 1000
5) Redo step 3.

Expected result: OnDrag should work across entire Game view(it is set up that way).
Actual result: OnDrag doesn't work in upper/lower/right/left ~10% of the screen. (percentage may differ between 5.3 and 5.4)

Important note: Changing Perspective camera Clipping Planes Far value to default (current one is set to lower(than default) by the user), resolves the issue.

Reproduced with: 5.3.3p3 , 5.4.0b10